Exhibit 99.1

STAGWELL INC. (NASDAQ: STGW) REPORTS STANDALONE MDC PARTNERS INC. RESULTS FOR THE

THREE AND SIX MONTHS ENDED JUNE 30, 2021

Strong quarterly revenue growth of 33% year-over-year to $346 million

Second quarter Net Income attributable to MDC Partners common shareholders of $1.7 million

Record second quarter Adjusted EBITDA of $60 million, up 67% from the prior period

SECOND QUARTER & YTD MDC PARTNERS INC. HIGHLIGHTS:

New York, NY, August 4, 2021 (NASDAQ: STGW) – Stagwell Inc. (“Stagwell”) today announced MDC Partners Inc. (“MDC Partners,” “legacy MDC” or the “Company”) financial results for the three and six months ended June 30, 2021.

"Stagwell is coming out of the gate firing on all cylinders. We are pleased to report industry-leading revenue growth and record second quarter Adjusted EBITDA at legacy MDC,” said Mark Penn, Chairman and Chief Executive Officer of Stagwell. “We are encouraged by the continued strength through the first half of the year and saw broad-based growth across the network. Our digital businesses saw another quarter of high double-digit growth and our creative agencies won considerable new business during the active second quarter pitch season. These results show the potential of our combined platform that brings together culture-moving creativity and leading-edge technology onto a single, integrated platform.”

Second Quarter and Year-to-Date 2021 MDC Partners Standalone Financial Results

Revenue for the second quarter of 2021 was $345.6 million versus $259.7 million for the second quarter 2020, an increase of 33.1%. The effect on revenue of foreign exchange was positive 1.8% and the organic revenue increase was 31.3%, inclusive of $19.0 million or 446 basis points from higher billable costs. Organic revenue increased primarily due to a continuation of the recovery in spending by clients begun in the first quarter.

Revenue in the second quarter of 2021 increased 12.4% sequentially from the first quarter, as revenue continues to rebound from the impact of the pandemic. Net New Business wins in the second quarter of 2021 totaled $56.9 million as we capitalized on a particularly active pitch season.

Net income attributable to MDC Partners common shareholders for the second quarter of 2021 was $1.7 million versus a net loss of $4.1 million for the second quarter of 2020. The increase was primarily due to higher revenues in the quarter, as well as the favorable impact of foreign exchange. Diluted income per share attributable to MDC Partners common shareholders for the second quarter of 2021 was $0.02 versus diluted loss per share of $0.06 for the second quarter of 2020.

Adjusted EBITDA for the second quarter of 2021 was $60.3 million versus $36.2 million for the second quarter of 2020, an increase of 66.7%, primarily due to higher revenues, partially offset by an increase in operating expense. This led to a 350 basis point increase in Adjusted EBITDA margin in the second quarter of 2021 to 17.4% from 13.9% in the second quarter of 2020.

Covenant EBITDA for the last twelve months (LTM) was $220.1 million as of June 30, 2021, up from $193.3 million in the second quarter of 2020.

Revenue for the first six months of 2021 was $653.2 million versus $587.4 million in the prior year period. The effect on revenue of foreign exchange was positive 1.6%, the impact of non-GAAP acquisitions (dispositions), net was negative 0.4%, and the organic revenue increase was 10.0%.

Net income attributable to MDC Partners Inc. common shareholders for the first six months of 2021 was $2.6 million versus net loss of $6.5 million for the first six months of 2020. The increase was primarily due to higher revenues, partially offset by an increase in operating expenses. Diluted income per share attributable to MDC Partners common shareholders for the six months of 2021 was $0.03 versus diluted loss per share of $0.09 for the first six months of 2020.

Adjusted EBITDA for the first six months of 2021 was $112.2 million versus $75.7 million in the first six months of 2020, an increase of 48.2%. This lead to an Adjusted EBITDA Margin of 17.2% versus 12.9% in prior year period, an increase of 430 basis points.

Stagwell Inc. Financial Outlook

2021 financial guidance is as follows:

Stagwell Inc. Conference Call

Management will host a video webcast and conference call on Wednesday, August 4, 2021, at 8:30 a.m. (ET) to discuss standalone results for Stagwell Marketing Group LLC and MDC Partners Inc for the three and six months ended June 30, 2021. The video webcast will be accessible at https://kvgo.com/openexchange-inc/mdca-stagwell-earnings-call. An investor presentation has been posted on our website at www.stagwellglobal.com and may be referred to during the conference call.

A recording of the conference call will be accessible one hour after the call and available for ninety days at www.stagwellglobal.com.

About Stagwell Inc.

Stagwell is the challenger holding company built to transform marketing. We deliver scaled creative performance for the world’s most ambitious brands, connecting culture-moving creativity with leading-edge technology to harmonize the art and science of marketing. Led by entrepreneurs, our 10,000+ specialists in 30+ countries are unified under a single purpose: to drive effectiveness and improve business results for our clients. Stagwell Inc. is the successor SEC Registrant to MDC Partners Inc. Join us at www.stagwellglobal.com.

Non-GAAP Financial Measures

In addition to its MDC Partners Inc. reported results, Stagwell Inc has included in this earnings release certain financial results that the Securities and Exchange Commission (SEC) defines as "non-GAAP Financial Measures." Management believes that such non-GAAP financial measures, when read in conjunction with the Company's reported results, can provide useful supplemental information for investors analyzing period to period comparisons of the Company's results. Such non-GAAP financial measures include the following:

(1) Organic Revenue: “Organic revenue growth” and “organic revenue decline” refer to the positive or negative results, respectively, of subtracting both the foreign exchange and acquisition (disposition) components from total revenue growth. The acquisition (disposition) component is calculated by aggregating prior period revenue for any acquired businesses, less the prior period revenue of any businesses that were disposed of during the current period. The organic revenue growth (decline) component reflects the constant currency impact of (a) the change in revenue of the partner firms that the Company has held throughout each of the comparable periods presented, and (b) “non-GAAP acquisitions (dispositions), net”. Non-GAAP acquisitions (dispositions), net consists of (i) for acquisitions during the current year, the revenue effect from such acquisition as if the acquisition had been owned during the equivalent period in the prior year and (ii) for acquisitions during the previous year, the revenue effect from such acquisitions as if they had been owned during that entire year (or same period as the current reportable period), taking into account their respective pre-acquisition revenues for the applicable periods, and (iii) for dispositions, the revenue effect from such disposition as if they had been disposed of during the equivalent period in the prior year.

(2) Net New Business: Estimate of annualized revenue for new wins less annualized revenue for losses incurred in the period.

(3) Adjusted EBITDA: Adjusted EBITDA is a non-GAAP financial measure that represents Net income (loss) attributable to MDC Partners Inc. common shareholders plus or minus non-operating items to operating income (loss) plus depreciation and amortization, stock-based compensation, deferred acquisition consideration adjustments, distributions from non-consolidated affiliates, and other items, net which includes items such as merger related costs, severance and other restructuring expenses, including costs for leases that will either be terminated or sublet in connection with the centralization of our New York real estate portfolio.

(4) Covenant EBITDA: Covenant EBITDA is a measure that includes pro forma adjustments for acquisitions, one-time charges, permitted dispositions and other items, as defined in the Company's Credit Agreement. We believe that the presentation of Covenant EBITDA is useful to investors as it eliminates the effect of certain non-cash and other items not necessarily indicative of a company’s underlying operating performance. In addition, the presentation of Covenant EBITDA provides additional information to investors about the calculation of, and compliance with, certain financial covenants in the Company's Credit Agreement.

(5) Financial Guidance: The Company provides guidance on a non-GAAP basis as it cannot predict certain elements which are included in reported GAAP results.

Included in this earnings release are tables reconciling reported MDC Partners Inc. results to arrive at certain of these non-GAAP financial measures.

This press release contains forward-looking statements. Statements in this press release that are not historical facts, including without limitation the information under the heading "Financial Outlook" and statements about the Company’s beliefs and expectations, earnings (loss) guidance, recent business and economic trends, potential acquisitions, and estimates of amounts for redeemable noncontrolling interests and deferred acquisition consideration, constitute forward-looking statements. Words such as “estimates”, “expects”, “contemplates”, “will”, “anticipates”, “projects”, “plans”, “intends”, “believes”, “forecasts”, “may”, “should”, and variations of such words or similar expressions are intended to identify forward-looking statements. These statements are based on current plans, estimates and projections, and are subject to change based on a number of factors, including those outlined in this section. Forward-looking statements speak only as of the date they are made, and the Company undertakes no obligation to update publicly any of them in light of new information or future events, if any.

Forward-looking statements involve inherent risks and uncertainties. A number of important factors could cause actual results to differ materially from those contained in any forward-looking statements. Such risk factors include, but are not limited to, the following:

Investors should carefully consider these risk factors, other risk factors described herein, and the additional risk factors outlined in more detail in the Company’s 2020 Form 10-K, filed with the Securities and Exchange Commission (the “SEC”) on March 16, 2021 and accessible on the SEC’s website at www.sec.gov., under the caption “Risk Factors,” and in the Company’s other SEC filings.

⁽¹⁾ Organic revenue refers to the positive results of subtracting both the foreign exchange and acquisition (disposition) components from total revenue growth. The acquisition (disposition) component is calculated by aggregating prior period revenue for any acquired businesses, less the prior period revenue of any businesses that were disposed of during the current period. The organic revenue component reflects the constant currency impact of (a) the change in revenue of the partner firms which the Company has held throughout each of the comparable periods presented, and (b) “non-GAAP acquisitions (dispositions), net”. Non-GAAP acquisitions (dispositions), net consists of (i) for acquisitions during the current year, the revenue effect from such acquisition as if the acquisition had been owned during the equivalent period in the prior year and (ii) for acquisitions during the previous year, the revenue effect from such acquisitions as if they had been owned during that entire year (or same period as the current reportable period), taking into account their respective pre-acquisition revenues for the applicable periods, and (iii) for dispositions, the revenue effect from such disposition as if they had been disposed of during the equivalent period in the prior year. See "Non-GAAP Financial Measures" herein.

Note: Actuals may not foot due to rounding.

SCHEDULE 3

MDC PARTNERS INC.

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA

(US$ in 000s, except percentages)

⁽¹⁾ Distributions from non-consolidated affiliates includes (i) cash received for profit distributions from non-consolidated affiliates, and (ii) consideration from the sale of ownership interests in non-consolidated affiliates less contributions to date plus undistributed earnings (losses).

⁽²⁾ Other items, net includes items such as merger related costs, severance and other restructuring expenses. See Schedule 10 for a reconciliation of amounts.

⁽³⁾ Adjusted EBITDA is a non-GAAP financial measure, and as shown above it represents operating income (loss) plus depreciation and amortization, stock-based compensation, deferred acquisition consideration adjustments, distributions from non-consolidated affiliates, impairment and other items. See "Non-GAAP Financial Measures" herein.

Note: Actuals may not foot due to rounding.

SCHEDULE 4

MDC PARTNERS INC.

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA

(US$ in 000s, except percentages)

⁽¹⁾ Distributions from non-consolidated affiliates includes (i) cash received for profit distributions from non-consolidated affiliates, and (ii) consideration from the sale of ownership interests in non-consolidated affiliates less contributions to date plus undistributed earnings (losses).

⁽²⁾ Other items, net includes items such as merger related costs, severance and other restructuring expenses. See Schedule 10 for a reconciliation of amounts.

⁽³⁾ Adjusted EBITDA is a non-GAAP financial measure, and as shown above it represents operating income (loss) plus depreciation and amortization, stock-based compensation, deferred acquisition consideration adjustments, distributions from non-consolidated affiliates, impairment and other items. See "Non-GAAP Financial Measures" herein.

Note: Actuals may not foot due to rounding.

SCHEDULE 5

MDC PARTNERS INC.

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA

(US$ in 000s, except percentages)

⁽¹⁾ Distributions from non-consolidated affiliates includes (i) cash received for profit distributions from non-consolidated affiliates, and (ii) consideration from the sale of ownership interests in non-consolidated affiliates less contributions to date plus undistributed earnings (losses).

⁽²⁾ Other items, net includes items such as merger related costs, severance and other restructuring expenses. See Schedule 10 for a reconciliation of amounts.

⁽³⁾ Adjusted EBITDA is a non-GAAP financial measure, and as shown above it represents operating income (loss) plus depreciation and amortization, stock-based compensation, deferred acquisition consideration adjustments, distributions from non-consolidated affiliates, impairment and other items. See "Non-GAAP Financial Measures" herein.

Note: Actuals may not foot due to rounding.

SCHEDULE 6

MDC PARTNERS INC.

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA

(US$ in 000s, except percentages)

⁽¹⁾ Distributions from non-consolidated affiliates includes (i) cash received for profit distributions from non-consolidated affiliates, and (ii) consideration from the sale of ownership interests in non-consolidated affiliates less contributions to date plus undistributed earnings (losses).

⁽²⁾ Other items, net includes items such as merger related costs, severance and other restructuring expenses. See Schedule 10 for a reconciliation of amounts.

⁽³⁾ Adjusted EBITDA is a non-GAAP financial measure, and as shown above it represents operating income (loss) plus depreciation and amortization, stock-based compensation, deferred acquisition consideration adjustments, distributions from non-consolidated affiliates, impairment and other items. See "Non-GAAP Financial Measures" herein.

Note: Actuals may not foot due to rounding.

⁽¹⁾ Covenant EBITDA is a measure that includes pro forma adjustments for acquisitions, one-time charges, permitted dispositions and other adjustments, as defined in the Company's Credit Agreement. Covenant EBITDA is calculated as the aggregate of operating results for the rolling last twelve months (LTM). Each quarter is presented to provide the information utilized to calculate Covenant EBITDA. Historical Covenant EBITDA may be re-casted in the current period for any proforma adjustments related to acquisitions and/or dispositions in the current period. See "Non-GAAP Financial Measures" herein.

⁽²⁾ Other items, net includes items such as merger related costs, severance and other restructuring expenses. See Schedule 10 for a reconciliation of amounts.

⁽³⁾ Other adjustments, net primarily includes one-time professional fees and costs associated with real estate consolidation.

Note: Actuals may not foot due to rounding.

Note: Actuals may not foot due to rounding.

Net revenue, primarily consisting of fees, commissions and performance incentives, represents the amount of our gross billings excluding billable expenses charged to a client. Net revenue of $298,368 (exclusive of billable expenses of $47,237) for the quarter ended June 30, 2021, increased from $231,911 (exclusive of billable expenses of $27,766) from the quarter ended June 30, 2020.

⁽¹⁾ Contribution to organic revenue represents the change in revenue, measured on a constant currency basis, relative to the comparable pre-acquisition period for acquired businesses that are included in the Company's organic revenue growth (decline) calculation.

⁽²⁾ Prior year revenue from dispositions reflects the incremental impact on revenue for the comparable period after the Company's disposition of such disposed business, plus revenue from each business disposed of by the Company in the previous year through the twelve month anniversary of the disposition.

Note: Actuals may not foot due to rounding.

Exhibit 99.2

Management Presentation Legacy MDC Partners Standalone Second Quarter 2021 Results August 4, 2021

2 This presentation contains forward - looking statements . Statements in this presentation that are not historical facts, including without limitation the information under the heading "Financial Outlook" and statements about the Company’s beliefs and expectations, earnings (loss) guidance, recent business and economic trends, potential acquisitions, and estimates of amounts for redeemable noncontrolling interests and deferred acquisition consideration, constitute forward - looking statements . Words such as “estimates”, “expects”, “contemplates”, “will”, “anticipates”, “projects”, “plans”, “intends”, “believes”, “forecasts”, “may”, “should”, and variations of such words or similar expressions are intended to identify forward - looking statements . These statements are based on current plans, estimates and projections, and are subject to change based on a number of factors, including those outlined in this section . Forward - looking statements speak only as of the date they are made, and the Company undertakes no obligation to update publicly any of them in light of new information or future events, if any . Forward - looking statements involve inherent risks and uncertainties . A number of important factors could cause actual results to differ materially from those contained in any forward - looking statements . Such risk factors include, but are not limited to, the following : • risks associated with international, national and regional unfavorable economic conditions that could affect the Company or its clients, including as a result of the novel coronavirus pandemic (“COVID - 19 ”) ; • the effects of the outbreak of COVID - 19 , including the measures to reduce its spread, and the impact on the economy and demand for our services, which may precipitate or exacerbate other risks and uncertainties ; • an inability to realize expected benefits of the redomiciliation of the Company from the federal jurisdiction of Canada to the State of Delaware (the “Redomiciliation”) and the subsequent combination of the Company’s business with the business of the subsidiaries of Stagwell Media LP (“Stagwell”) that own and operate a portfolio of marketing services companies (the “Business Combination” and, together with the Redomiciliation, the “Transactions”) or the occurrence of difficulties in connection with the Transactions ; • adverse tax consequences in connection with the Transactions for the Company, its operations and its shareholders, that may differ from the expectations of the Company, including that future changes in tax law, potential increases to corporate tax rates in the United States and disagreements with the tax authorities on the Company’s determination of value and computations of its attributes may result in increased tax costs ; • the occurrence of material Canadian federal income tax (including material “emigration tax”) as a result of the Transactions ; • the impact of uncertainty associated with the Transactions on the Company’s businesses ; • direct or indirect costs associated with the Transactions, which could be greater than expected ; • risks associated with severe effects of international, national and regional economic conditions ; • the risk of parties challenging the Transactions or the impact of the Transactions on the Company’s debt arrangements ; • the Company’s ability to attract new clients and retain existing clients; • reduction in client spending and changes in client advertising, marketing and corporate communications requirements ; FORWARD LOOKING STATEMENTS & OTHER INFORMATION

3 • financial failure of the Company’s clients ; • the Company’s ability to retain and attract key employees ; • the Company’s ability to achieve the full amount of its stated cost saving initiatives ; • the Company’s implementation of strategic initiatives ; • the Company’s ability to remain in compliance with its debt agreements and the Company’s ability to finance its contingent payment obligations when due and payable, including but not limited to those relating to redeemable noncontrolling interests and deferred acquisition consideration ; • the successful completion and integration of acquisitions which complement and expand the Company’s business capabilities ; and • foreign currency fluctuations . Investors should carefully consider these risk factors and the additional risk factors outlined in more detail in the Company's Annual Report on Form 10 - K and in the Company’s other SEC filings . FORWARD LOOKING STATEMENTS & OTHER INFORMATION (Cont.)

4 SUMMARY • Organic revenue increased 31 . 3 % in the second quarter and 10 . 0 % YTD . • Net income attributable to MDC Partners common shareholders of $ 1 . 7 million in the second quarter of 2021 versus net loss of $ 4 . 1 million in the prior year period ; and net income of $ 2 . 6 million in the six months ended June 30 , 2021 versus net loss of $ 6 . 5 million in the prior year period • Adjusted EBITDA of $ 60 . 3 million versus $ 36 . 2 million in the prior year period, an increase of 66 . 7 % ; and $ 112 . 2 million for six months ended June 30 , 2021 versus $ 75 . 7 million in the prior year period, an increase of 48 . 2 % • Net revenue of $ 298 . 4 million in the second quarter versus $ 231 . 9 million in the prior year period, an increase of 28 . 7 % ; and $ 569 . 1 million in the six months ended June 30 , 2021 versus $ 506 . 4 million in the prior year period, an increase of 12 . 4 % • Net new business wins of $ 56 . 9 million in the second quarter and $ 128 . 5 million over the last twelve months • Covenant EBITDA (LTM) of $ 220 . 1 million, up from $ 193 . 3 million in the second quarter of 2020 Note: See appendix for definitions of Non - GAAP Financial Measures

5 ----- DRAFT ----- • Revenue of $ 345 . 6 million versus $ 259 . 7 million in the prior year period, an increase of 33 . 1 % • Organic revenue increased by 31 . 3 % versus the prior year period . • Organic revenue was favorably impacted by 446 basis points from billable pass - through costs • Net revenue of $ 298 . 4 million in the first quarter versus $ 231 . 9 million in the prior year period, an increase of 28 . 7 % • Organic net revenue increased 26 . 9 % versus the prior year period • Net income attributable to MDC Partners common shareholders of $ 1 . 7 million in the second quarter of 2021 versus net loss of $ 4 . 1 million in the prior year period • Adjusted EBITDA of $ 60 . 3 million versus $ 36 . 2 million in the prior year period, an increase of 66 . 7 % • Adjusted EBITDA Margin was 17 . 4 % vs . 13 . 9 % in prior year period, an increase of 350 basis points • Covenant EBITDA (LTM) of $ 220 . 1 million, up from $ 193 . 3 million in the second quarter of 2020 • Net new business wins of $ 56 . 9 million in the second quarter versus $ 20 . 5 million a year ago and totaled $ 128 . 5 million over the last twelve months • Leverage of 4 . 1 x, improved from 4 . 6 x a year ago and in line with the first quarter of 2021 SECOND QUARTER 2021 FINANCIAL HIGHLIGHTS Note: See appendix for definitions of Non - GAAP Financial Measures

6 ----- DRAFT ----- • Revenue of $ 653 . 2 million versus $ 587 . 4 million in the prior year period • Organic revenue increased by 10 . 0 % versus the prior year period . Organic revenue was unfavorably impacted by 118 basis points from billable pass through costs • Adjusted EBITDA was $ 112 . 2 million versus $ 75 . 7 million in the prior year period, an increase of 48 . 2 % • Adjusted EBITDA Margin was 17 . 2 % vs . 12 . 9 % in prior year, an increase of 430 basis points • Net new business wins of $ 67 . 1 million SIX MONTHS 2021 FINANCIAL HIGHLIGHTS Note: See appendix for definitions of Non - GAAP Financial Measures

7 CONSOLIDATED REVENUE AND EARNINGS (US$ in millions, except percentages) Three Months Ended June 30, Six Months Ended June 30, 2021 2020 % Change 2021 2020 % Change Revenue $ 345.6 $ 259.7 33.1 % $ 653.2 $ 587.4 11.2 % Operating Expenses Cost of services sold 224.4 165.6 35.5 % 411.3 388.3 5.9 % Office and general expenses 80.5 66.2 21.7 % 164.5 132.6 24.1 % Depreciation and amortization 8.0 8.9 (10.0 ) % 16.2 18.1 (10.6 ) % Impairment and other losses — 18.8 (100.0 ) % 0.9 19.0 (95.4 ) % Operating income 32.6 0.1 NM % 60.3 29.4 NM % Interest expense and finance charges, net (19.5 ) (15.9 ) (38.6 ) (31.6 ) Foreign exchange gain (loss) 1.9 5.3 4.0 (9.4 ) Other, net 0.8 5.9 1.5 22.2 Income tax expense (benefit) 1.4 (7.9 ) 2.7 5.6 Equity in losses of non - consolidated affiliates (0.2 ) (0.8 ) (0.6 ) (0.8 ) Net income 14.3 2.5 23.8 4.3 Net income attributable to the noncontrolling interest (8.2 ) (3.1 ) (12.7 ) (3.9 ) Accretion on and net income allocated to convertible preference shares (4.5 ) (3.5 ) (8.5 ) (6.9 ) Net income (loss) attributable to MDC Partners Inc. common shareholders $ 1.7 $ (4.1 ) $ 2.6 $ (6.5 ) Note: See appendix for definitions of Non - GAAP Financial Measures Note: Actuals may not foot due to rounding

8 Organic revenue increased 31.3% in the second quarter of 2021 versus the prior year period. Organic revenue increased by 10.0 % f or the first six months of 2021 versus the prior year period. REVENUE SUMMARY (US$ in millions, except percentages) Three Months Ended Six Months Ended Revenue $ % Change Revenue $ % Change June 30, 2020 $ 259.7 $ 587.4 Organic revenue 81.3 31.3 % 58.7 10.0 % Non - GAAP acquisitions (dispositions), net — — % (2.1 ) (0.4 ) % Foreign exchange impact 4.6 1.8 % 9.2 1.6 % Total Change 85.9 33.1 % 65.8 11.2 % June 30, 2021 $ 345.6 $ 653.2 Note: Actuals may not foot due to rounding

9 REVENUE BY GEOGRAPHY AND SEGMENT Note: Actuals may not foot due to rounding (US$ in millions, except percentages) 2020 2021 Q2 Q3 Q4 Q1 Q2 Total Total Organic Revenue Total Total Organic Revenue Total Total Organic Revenue Total Total Organic Revenue Total Total Organic Revenue Revenue Growth Growth (Decline) Revenue Growth Growth (Decline) Revenue Growth Growth (Decline) Revenue Growth Growth (Decline) Revenue Growth Growth (Decline) United States $ 210.3 (26.1 )% (24.7 )% $ 228.3 (16.0 )% (14.5 )% $ 256.5 (13.6 )% (12.1 )% $ 242.6 (8.3 )% (7.5 )% $ 277.5 31.9 % 31.9 % Canada 16.6 (32.4 )% (28.9 )% 20.3 (21.6 )% (20.9 )% 26.8 (17.0 )% (18.4 )% 22.7 24.1 % 17.5 % 23.0 38.4 % 28.3 % North America 227.0 (26.6 )% (25.0 )% 248.6 (16.5 )% (15.0 )% 283.2 (13.9 )% (12.7 )% 265.2 (6.2 )% (5.9 )% 300.5 32.4 % 31.7 % Other 32.7 (38.1 )% (34.2 )% 34.9 (23.1 )% (25.4 )% 44.9 (15.3 )% (19.8 )% 42.4 (5.7 )% (13.2 )% 45.1 37.7 % 28.8 % Total $ 259.7 (28.3 )% (26.4 )% $ 283.4 (17.3 )% (16.4 )% $ 328.2 (14.1 )% (13.7 )% $ 307.6 (6.2 )% (6.9 )% $ 345.6 33.1 % 31.3 % Integrated Networks - Group A $ 82.7 (19.9 )% (19.2 )% $ 87.1 (12.3 )% (12.7 )% $ 119.2 2.9 % 2.3 % $ 102.4 13.0 % 11.8 % $ 118.0 42.6 % 41.1 % Integrated Networks - Group B 93.4 (30.0 )% (29.0 )% 112.2 (13.1 )% (12.8 )% 112.3 (17.5 )% (17.7 )% 111.2 (5.6 )% (6.3 )% 123.5 32.2 % 31.0 % Media & Data Network 28.6 (27.6 )% (26.7 )% 33.6 (7.3 )% (7.3 )% 35.8 (15.7 )% (16.1 )% 36.8 (10.4 )% (12.2 )% 37.5 31.4 % 29.2 % All Other 55.0 (36.1 )% (30.7 )% 50.6 (35.4 )% (31.2 )% 60.8 (30.6 )% (27.3 )% 57.3 (26.9 )% (26.6 )% 66.6 21.1 % 18.3 % Total $ 259.7 (28.3 )% (26.4 )% $ 283.4 (17.3 )% (16.4 )% $ 328.2 (14.1 )% (13.7 )% $ 307.6 (6.2 )% (6.9 )% $ 345.6 33.1 % 31.3 %

10 REVENUE BY GEOGRAPHY AND SEGMENT Note : Actuals may not foot due to rounding (US$ in millions, except percentages) Six Months Ended June 30, 2020 2021 Total Total Organic Revenue Total Total Organic Revenue Revenue Growth Growth (Decline) Revenue Growth Growth (Decline) United States $ 474.9 (13.3 )% (12.2 )% $ 520.1 9.5 % 10.0 % Canada 34.9 (25.7 )% (16.0 )% 45.6 30.9 % 22.7 % North America 509.8 (14.3 )% (12.5 )% 565.8 11.0 % 10.8 % Other 77.7 (19.4 )% (15.4 )% 87.4 12.6 % 4.5 % Total $ 587.4 (15.0 )% (12.9 )% $ 653.2 11.2 % 10.0 % Integrated Networks - Group A $ 173.4 (2.1 )% (1.5 )% $ 220.4 27.1 % 25.8 % Integrated Networks - Group B 211.1 (20.8 )% (20.0 )% 234.6 11.1 % 10.2 % Media & Data Network 69.6 (15.8 )% (15.1 )% 74.3 6.7 % 4.8 % All Other 133.3 (19.0 )% (12.5 )% 123.9 (7.1 )% (8.1 )% Total $ 587.4 (15.0 )% (12.9 )% $ 653.2 11.2 % 10.0 %

11 Top 10 clients increased to 24% of revenue versus 22% a year ago (largest <4.9%) REVENUE BY CLIENT INDUSTRY Q2 2021 QTD Q2 2021 YTD Above 10% Food & Beverage, Consumer Products, Communications, Technology, Healthcare, Financials, Transportation/Lodging, Other Food & Beverage, Consumer Products, Technology, Healthcare, Financials, Other 0% to 10% Retail and Automotive N/A Below 0% N/A Retail, Communications, Automotive, Transportation and Travel/Lodging Year - over - Year Growth by Category Q2 2021 Mix

12 ADJUSTED EBITDA 1 Adjusted EBITDA is a non - GAAP financial measure. See appendix for the definition Note: Actuals may not foot due to rounding. (US$ in millions, except percentages) % Change 2020 2021 Q2 2021 vs. Q2 2020 Q2 Q3 Q4 Q1 Q2 Integrated Networks - Group A $ 17.2 $ 21.0 $ 25.3 $ 22.5 $ 27.3 58.4 % Integrated Networks - Group B 16.4 29.6 21.2 25.9 26.5 62.0 % Media & Data Network 0.9 3.0 4.0 5.1 6.9 NM % All Other 6.9 7.1 6.8 6.0 8.2 19.6 % Corporate (5.2 ) (6.7 ) (9.7 ) (7.5 ) (8.6 ) 65.9 % Adjusted EBITDA (1) $ 36.2 $ 54.1 $ 47.5 $ 51.9 $ 60.3 66.7 % Adjusted EBITDA margin 13.9 % 19.1 % 14.5 % 16.9 % 17.4 %

13 ADJUSTED EBITDA (1) Adjusted EBITDA is a non - GAAP financial measure. See appendix for the definition. Note: Actuals may not foot due to rounding. (US$ in millions, except percentages) Six Months Ended June 30, 2021 2020 % Change Integrated Networks - Group A $ 49.7 $ 33.5 48.4 % Integrated Networks - Group B 52.4 33.5 56.3 % Media & Data Network 12.0 2.7 NM % All Other 14.3 16.8 (15.0 ) % Corporate (16.2 ) (10.8 ) 50.0 % Adjusted EBITDA (1) $ 112.2 $ 75.7 48.2 % Adjusted EBITDA margin 17.2 % 12.9 %

14 COVENANT EBITDA 2020 2021 Covenant EBITDA (LTM) (1) (US$ in millions) Q2 Q3 Q4 Q1 Q2 Q1 - 2021 - LTM Q2 - 2021 - LTM Net income (loss) attributable to MDC Partners Inc. common shareholders $ (4.1 ) $ 0.4 $ (237.1 ) $ 0.9 $ 1.7 $ (239.9 ) $ (234.2 ) Adjustments to reconcile to operating income (loss): Accretion on and net income allocated to convertible preference shares 3.5 3.7 3.7 4.1 4.5 15.0 15.9 Net income attributable to the noncontrolling interest 3.1 10.7 7.2 4.5 8.2 25.5 30.6 Equity in losses of non - consolidated affiliates 0.8 — 1.4 0.5 0.2 2.7 2.1 Income tax expense (benefit) (7.9 ) 1.5 109.5 1.3 1.4 104.4 113.7 Interest expense and finance charges, net 15.9 15.3 15.3 19.1 19.5 65.6 69.2 Foreign exchange gain (5.3 ) (2.2 ) (6.3 ) (2.1 ) (1.9 ) (15.9 ) (12.4 ) Other, net (5.9 ) (0.5 ) 2.2 (0.6 ) (0.8 ) (4.8 ) 0.3 Operating income (loss) $ 0.1 $ 28.9 $ (104.1 ) $ 27.7 $ 32.6 $ (47.4 ) $ (14.9 ) Adjustments to reconcile to Adjusted EBITDA: Depreciation and amortization $ 8.9 $ 9.3 $ 9.5 $ 8.2 $ 8.0 $ 35.9 $ 35.0 Impairment and other losses 18.8 0.2 77.2 0.9 — 97.1 78.3 Stock - based compensation 1.0 6.5 3.6 (2.0 ) 6.9 9.1 15.0 Deferred acquisition consideration 2.3 2.8 41.7 11.7 5.6 58.5 61.8 Distributions from non - consolidated affiliates 1.1 0.2 0.9 — 0.5 2.2 1.6 Other items, net (2) 3.9 6.2 18.7 5.5 6.6 34.3 37.0 Adjusted EBITDA $ 36.2 $ 54.1 $ 47.5 $ 51.9 $ 60.3 $ 189.7 $ 213.8 Adjustments to reconcile to Covenant EBITDA: Severance due to eliminated positions 5.2 2.3 2.0 0.5 0.7 10.1 5.6 Other adjustments, net (3) 0.2 0.1 0.6 0.1 — 1.0 0.7 $ 41.6 $ 56.5 $ 50.1 $ 52.5 $ 61.0 $ 200.7 $ 220.1 ( 1 ) Covenant EBITDA is a measure that includes pro forma adjustments for acquisitions, one - time charges, permitted dispositions and other adjustments, as defined in the Company's Credit Agreement . Covenant EBITDA is calculated as the aggregate of operating results for the rolling last twelve months (LTM) . Each quarter is presented to provide the information utilized to calculate Covenant EBITDA . Historical Covenant EBITDA may be re - casted in the current period for any proforma adjustments related to acquisitions and/or dispositions in the current period . See "Non - GAAP Financial Measures" herein . ( 2 ) Other items, net includes items such as merger related costs, severance expense, other restructuring expenses and costs associated with the Company's strategic review process . (3) Other adjustments, net primarily includes one - time professional fees and costs associated with real estate consolidation.
 Note: Actuals may not foot due to rounding.

15 SUMMARY OF CASH FLOW (US$ in millions) Six Months Ended June 30, 2021 2020 Net cash provided by (used in) operating activities $ 10.4 $ (33.7 ) Net cash provided by (used in) investing activities (9.6 ) 14.6 Net cash provided by (used in) financing activities 46.9 (1.4 ) Effect of exchange rate changes on cash and cash equivalents (0.2 ) (1.0 ) Net increase in cash and cash equivalents 47.5 (21.5 ) Cash and cash equivalents at beginning of period 60.8 106.9 Cash and cash equivalents at end of period $ 108.3 $ 85.5 Supplemental disclosures: Cash income taxes paid $ 7.9 $ 2.6 Cash interest paid $ 32.8 $ 28.7 Note: Actuals may not foot due to rounding.

16 2021 FINANCIAL OUTLOOK 2021 financial guidance is as follows : • Revenue for 2021 , on a pro forma basis giving effect to the combination as if it was completed on January 1 , 2021 , is estimated to be $ 2 . 135 to $ 2 . 180 billion, including an estimated $ 762 million for MDC for the seven - month period ending July 31 , 2021 . • Adjusted EBITDA for 2021 , on a pro forma basis giving effect to the combination as if it was completed on January 1 , 2021 , is estimated to be $ 342 to $ 357 million, including an estimated $ 128 million for MDC for the seven - month period ending July 31 , 2021 . • Guidance assumes no impact from foreign exchange or acquisitions or dispositions . * Stagwell has excluded a quantitative reconciliation with respect to the Company’s 2021 guidance under the “unreasonable eff ort s” exception in Item 10(e)(1)(i)(B) of Regulation S - K See "Non - GAAP Financial Measures" below for additional information. 2021 Outlook Commentary*

17 APPENDIX

18 REVENUE TRENDING SCHEDULE Note: See appendix for definitions of Non - GAAP Financial Measures Note: Actuals may not foot due to rounding (US$ in thousands, except percentages) 2020 2021 Q1 Q2 Q3 Q4 YTD Q1 Q2 YTD Revenue United States $ 264,561 $ 210,342 $ 228,256 $ 256,477 $ 959,636 $ 242,580 $ 277,542 $ 520,122 Canada 18,256 16,609 20,299 26,766 81,930 22,650 22,992 45,642 North America 282,817 226,951 248,555 283,243 1,041,566 265,230 300,534 565,764 Other 44,925 32,726 34,869 44,925 157,445 42,355 45,071 87,426 Total $ 327,742 $ 259,677 $ 283,424 $ 328,168 $ 1,199,011 $ 307,585 $ 345,605 $ 653,190 % of Revenue United States 80.7 % 81.0 % 80.5 % 78.2 % 80.1 % 78.9 % 80.3 % 79.6 % Canada 5.6 % 6.4 % 7.2 % 8.2 % 6.8 % 7.4 % 6.7 % 7.0 % North America 86.3 % 87.4 % 87.7 % 86.4 % 86.9 % 86.3 % 87.0 % 86.6 % Other 13.7 % 12.6 % 12.3 % 13.6 % 13.1 % 13.7 % 13.0 % 13.4 % Total 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % Total Growth % United States 0.6 % (26.1 )% (16.0 )% (13.6 )% (14.0 )% (8.3 )% 31.9 % 9.5 % Canada (18.4 )% (32.4 )% (21.6 )% (17.0 )% (22.0 )% 24.1 % 38.4 % 30.9 % North America (0.9 )% (26.6 )% (16.5 )% (13.9 )% (14.7 )% (6.2 )% 32.4 % 11.0 % Other 3.5 % (38.1 )% (23.1 )% (15.3 )% (19.1 )% (5.7 )% 37.7 % 12.6 % Total (0.3 ) % (28.3 ) % (17.3 ) % (14.1 ) % 15.3 % (6.2 ) % 33.1 % 11.2 % Organic Revenue Growth (Decline) % United States 1.3 % (24.7 )% (14.5 )% (12.1 )% (12.7 )% (7.5 )% 31.9 % 10.0 % Canada (1.7 )% (28.9 )% (20.9 )% (18.4 )% (17.9 )% 17.5 % 28.3 % 22.7 % North America 1.1 % (25.0 )% (15.0 )% (12.7 )% (13.2 )% (5.9 )% 31.7 % 10.8 % Other 7.6 % (34.2 )% (25.4 )% (19.8 )% (18.9 )% (13.2 )% 28.8 % 4.5 % Total 2.0 % (26.4 ) % (16.4 ) % (13.7 ) % (13.9 ) % (6.9 ) % 31.3 % 10.0 % Growth % from Foreign Exchange United States 0.0 % (0.0 )% 0.0 % 0.0 % 0.0 % 0.0 % 0.0 % 0.0 % Canada (0.1 )% (3.4 )% (0.7 )% 1.4 % (0.6 )% 6.5 % 10.1 % 8.2 % North America — % (0.3 )% (0.1 )% 0.1 % — % 0.4 % 0.7 % 0.6 % Other (4.1 )% (3.9 )% 2.3 % 4.5 % (0.2 )% 7.5 % 8.9 % 8.1 % Total (0.5 ) % (0.8 ) % 0.3 % 0.7 % (0.1 ) % 1.4 % 1.8 % 1.6 % Growth % from Acquisitions (Dispositions), net United States (0.8 )% (1.4 )% (1.5 )% (1.5 )% (1.3 )% (0.8 )% 0.0 % (0.4 )% Canada (16.6 )% 0.0 % 0.0 % 0.0 % (3.5 )% 0.0 % 0.0 % 0.0 % North America (2.0 )% (1.3 )% (1.4 )% (1.4 )% (1.5 )% (0.7 )% 0.0 % (0.4 )% Other 0.0 % 0.0 % 0.0 % 0.0 % 0.0 % 0.0 % 0.0 % 0.0 % Total (1.7 ) % (1.1 ) % (1.2 ) % (1.2 ) % (1.3 ) % (0.6 ) % — % (0.4 ) %

19 ADJUSTED EBITDA TRENDING SCHEDULE (1 ) Adjusted EBITDA is a non - GAAP financial measure. See appendix for the definition. Note: Actuals may not foot due to rounding (US$ in thousands) 2020 2021 Q1 Q2 Q3 Q4 YTD Q1 Q2 YTD PARTNER FIRMS Revenue: $ 327,742 $ 259,677 $ 283,424 $ 328,168 $ 1,199,011 $ 307,585 $ 345,605 $ 653,190 Operating income (loss) 37,665 11,921 43,651 (75,106 ) 18,131 39,409 46,687 86,096 Depreciation and amortization 8,974 8,662 9,133 8,755 35,524 6,960 6,820 13,780 Impairment and other losses 161 17,711 159 77,240 95,271 875 — 875 Stock - based compensation 2,928 763 5,038 2,468 11,197 (2,593 ) 6,384 3,791 Deferred acquisition consideration (4,600 ) 2,312 2,803 41,672 42,187 11,685 5,612 17,297 Other items, net — — — 2,240 2,240 3,118 3,417 6,535 Adjusted EBITDA (1) $ 45,128 $ 41,369 $ 60,784 $ 57,269 $ 204,550 $ 59,454 $ 68,920 $ 128,374 CORPORATE GROUP Revenue: $ — $ — $ — $ — $ — $ — $ — Operating loss (8,338 ) (11,823 ) (14,762 ) (28,967 ) (63,890 ) (11,742 ) (14,044 ) (25,786 ) Depreciation and amortization 232 236 199 713 1,380 1,216 1,185 2,401 Impairment and other losses — 1,129 — — 1,129 — — — Stock - based compensation 142 276 1,421 1,143 2,982 630 554 1,184 Distributions from non - consolidated affiliates (14 ) 1,079 208 902 2,175 9 463 472 Other items, net 2,416 3,895 6,208 16,485 29,004 2,367 3,202 5,569 Adjusted EBITDA (1) $ (5,562 ) $ (5,208 ) $ (6,726 ) $ (9,724 ) $ (27,220 ) $ (7,520 ) $ (8,640 ) $ (16,160 ) TOTAL Revenue: $ 327,742 $ 259,677 $ 283,424 $ 328,168 $ 1,199,011 $ 307,585 $ 345,605 $ 653,190 Operating income (loss) 29,327 98 28,889 (104,073 ) (45,759 ) 27,667 32,643 60,310 Depreciation and amortization 9,206 8,898 9,332 9,468 36,904 8,176 8,005 16,181 Impairment and other losses 161 18,840 159 77,240 96,400 875 — 875 Stock - based compensation 3,070 1,039 6,459 3,611 14,179 (1,963 ) 6,938 4,975 Deferred acquisition consideration (4,600 ) 2,312 2,803 41,672 42,187 11,685 5,612 17,297 Distributions from non - consolidated affiliates (14 ) 1,079 208 902 2,175 9 463 472 Other items, net 2,416 3,895 6,208 18,725 31,244 5,485 6,619 12,104 Adjusted EBITDA (1) $ 39,566 $ 36,161 $ 54,058 $ 47,545 $ 177,330 $ 51,934 $ 60,280 $ 112,214

20 RECONCILIATIONS (1) Contributions to organic revenue represents the change in revenue, measured on a constant currency basis, relative to the com pa rable pre - acquisition period for acquired businesses that is included in the Company's organic revenue growth (decline) calculation. (2) Prior year revenue from dispositions reflects the incremental impact on revenue for the comparable period after the Company's d isposition of such disposed business, plus revenue from each business disposed of by the Company in the previous year through the twelve month anniversary of the disposition. Note: Actuals may not foot due to rounding. (US$ in thousands) 2020 2021 Q1 Q2 Q3 Q4 YTD Q1 Q2 YTD NON - GAAP DISPOSITIONS, NET Foreign exchange impact $ (248 ) $ — $ — $ — $ (248 ) $ — $ — $ — Contribution to organic revenue (1) (411 ) — — — (411 ) — — — Prior year revenue from dispositions (2) (5,024 ) (4,106 ) (4,076 ) (4,447 ) (17,653 ) (2,101 ) — (2,101 ) Non - GAAP dispositions, net $ (5,683 ) $ (4,106 ) $ (4,076 ) $ (4,447 ) $ (18,312 ) $ (2,101 ) $ — $ (2,101 ) OTHER ITEMS, NET Severance and other restructuring expenses $ 1,334 $ 2,969 $ 3,270 $ 1,072 $ 8,645 $ 2,345 $ 2,632 $ 4,977 Merger costs 1,082 926 2,938 17,653 22,599 3,140 3,987 7,127 Total other items, net $ 2,416 $ 3,895 $ 6,208 $ 18,725 $ 31,244 $ 5,485 $ 6,619 $ 12,104 CAPITAL EXPENDITURES, NET Capital expenditures $ (1,546 ) $ (2,143 ) $ (24,188 ) $ (9,426 ) $ (37,303 ) $ (516 ) $ (1,567 ) $ (2,083 ) Net revenue, primarily consisting of fees, commissions and performance incentives, represents the amount of our gross billing s e xcluding billable expenses charged to a client. Net revenue of $298,368 (exclusive of billable expenses of $47,237) for the quarter ended June 30, 2021, increased from $231,911 (exclusive of billable expenses of $27,766) for the quarter ended June 30, 2020.

21 AVAILABLE LIQUIDITY 1 1 Subject to available borrowings under the Credit Facility. Note: Actuals may not foot due to rounding (US$ in millions) June 30, 2021 December 31, 2020 Commitment Under Facility $ 211.5 $ 211.5 Drawn 88.6 — Undrawn Letters of Credit 19.5 18.7 Undrawn Commitments Under Facility (1) $ 103.4 $ 192.8 Total Cash & Cash Equivalents 108.3 60.8 Liquidity $ 211.6 $ 253.6

22 CURRENT CREDIT PICTURE 1 These ratios and measures are not based on generally accepted accounting principles and are not presented as alternatives measures of operating performance or liquidity . Some of these ratios and measures include, among other things, pro forma adjustments for acquisitions, one - time charges, and other items, as defined in the Credit Agreement . They are presented here to demonstrate compliance with the covenants in the Credit Agreement, as non - compliance with such covenants could have a material adverse effect on the Company . 2 Covenant EBITDA is a measure that includes pro forma adjustments for acquisitions, one - time charges, and other items, as defined in the Credit Agreement . 3 Total Senior Leverage is a measure that includes borrowings under the Credit Agreement, outstanding letters of credit, less cash held in depository accounts, as defined in the Credit Agreement 4 Net Debt is a measure that includes borrowings under the Credit Agreement, the Senior Notes, other outstanding debt and letters of credit, less cash held in depository accounts, as defined in the Credit Agreement . Net Debt does not include Deferred Acquisition Consideration, and it does not include minority interest . 5 Based on borrowings as of June 30 , 2021 . Excludes letters of credit, and Deferred Acquisition Consideration . Note : Actuals may not foot due to rounding Current Debt Maturity Profile (5) $211.5 million Credit Facility Covenants (1) (US$ in millions) June 30, 2021 Covenants I. Total Senior Leverage Ratio 0.18 Maximum per covenant 2.00 II. Total Leverage Ratio 4.14 Maximum per covenant 5.50 III. Fixed Charges Ratio 2.44 Minimum per covenant 1.00 IV. Earnings before interest, taxes, depreciation and amortization (in millions) (2) $220.1 Minimum per covenant (in millions) $120.0 Debt Calculation Total Senior Leverage, net (3) $40.5 Net Debt (4) $910.7 Credit Facility 2024 Senior Notes

23 DEFINITION OF NON - GAAP FINANCIAL MEASURES In addition to its MDC Partners Inc reported results, Stagwell Inc . has included in its earnings release and supplemental management presentation certain financial results that the Securities and Exchange Commission defines as "non - GAAP financial measures . " Management believes that such non - GAAP financial measures, when read in conjunction with the Company's reported results, can provide useful supplemental information for investors analyzing period to period comparisons of the Company's results . Such non - GAAP financial measures include the following : Organic Revenue : Organic Revenue : “Organic revenue growth” and “organic revenue decline” refer to the positive or negative results, respectively, of subtracting both the foreign exchange and acquisition (disposition) components from total revenue growth . The acquisition (disposition) component is calculated by aggregating prior period revenue for any acquired businesses, less the prior period revenue of any businesses that were disposed of during the current period . The organic revenue growth (decline) component reflects the constant currency impact of (a) the change in revenue of the partner firms which the Company has held throughout each of the comparable periods presented, and (b) “non - GAAP acquisitions (dispositions), net” . Non - GAAP acquisitions (dispositions), net consists of (i) for acquisitions during the current year, the revenue effect from such acquisitions as if the acquisition had been owned during the equivalent period in the prior year and (ii) for acquisitions during the previous year, the revenue effect from such acquisitions as if they had been owned during that entire year (or same period as the current reportable period), taking into account their respective pre - acquisition revenues for the applicable periods, and (iii) for dispositions, the revenue effect from such dispositions as if they had been disposed of during the equivalent period in the prior year . Net New Business : Estimate of annualized revenue for new wins less annualized revenue for losses incurred in the period . Adjusted EBITDA : Adjusted EBITDA is a non - GAAP financial measure that represents Net income (loss) attributable to MDC Partners Inc . common shareholders plus or minus non - operating items to operating income (loss) plus depreciation and amortization, stock - based compensation, deferred acquisition consideration adjustments, distributions from non - consolidated affiliates, and other items, net which includes items such as merger related costs, severance expense and other restructuring expenses, including costs for leases that will either be terminated or sublet in connection with the centralization of our New York real estate portfolio . Covenant EBITDA : Covenant EBITDA is a measure that includes pro forma adjustments for acquisitions, one - time charges, permitted dispositions and other items, as defined in the Credit Agreement . We believe that the presentation of Covenant EBITDA is useful to investors as it eliminates the effect of certain non - cash and other items not necessarily indicative of a company’s underlying operating performance . In addition, the presentation of Covenant EBITDA provides additional information to investors about the calculation of, and compliance with, certain financial covenants in the Credit Agreement . Included in this earnings release are tables reconciling reported MDC Partners Inc . results to arrive at certain of these non - GAAP financial measures . Note: A reconciliation of non - GAAP to US GAAP reported results has been provided by the Company in the tables included herein.

MDC Partners One World Trade Center, Floor 65 New York, NY 10007 646 - 429 - 1800 www.stagwellglobal.com

Exhibit 99.3

STAGWELL MARKETING GROUP LLC REPORTS STANDALONE RESULTS FOR THE THREE AND SIX MONTHS ENDED JUNE 30, 2021

Results show significant growth including a 29.1% increase in GAAP revenue to $209.6m and a 39.5% increase in net revenue to $181.8m for Q2 2021 vs Q2 2020.

After adjusting for acquisitions, foreign exchange effects, and the election cycle, GAAP revenue for the quarter grew 43.9% with net revenue growth of 42.0%.

Second quarter net income increased to $18.7 million, representing 285.1% growth over Q2 2020.

Adjusted EBITDA increased 91.5% in Q2 2021 vs Q2 2020.

STAGWELL MARKETING GROUP HIGHLIGHTS: 2^nd QUARTER AND YTD JUNE 30, 2021

2^nd Quarter 2021:

Year to Date June 30, 2021:

Washington, DC, August 4, 2021 – Stagwell Marketing Group, which formally merged with MDC Partners to form Stagwell Inc. (Nasdaq: STGW) on August 2, announced standalone financial results for Stagwell Marketing Group LLC (“Stagwell” or the “Company”) for the three and six months ended June 30, 2021.

Current Stagwell Inc. President and former Stagwell Group Partner Jay Leveton stated, “The standalone Stagwell Marketing Group quarterly results show industry-leading, double digit net revenue growth across every one of our business segments. As the impact of the pandemic recedes, marketers are investing in research and data analytics to better understand changes among their stakeholders and improve how they connect with them through digital channels -- areas where Stagwell companies excel. We have excellent momentum as we launch Stagwell Inc.”

Current Stagwell Inc. COO and former Stagwell Group CFO Ryan Greene commented, “In the second quarter of 2021, due to its digital first nature, Stagwell’s net revenue grew robustly at 39.5% and EBITDA increased 91.5% as did net income, by 285.1% year over year. At a time when legacy holding companies are working to recover to 2019 pre-pandemic revenue levels, Stagwell’s GAAP revenue this past quarter is more than 20% higher and EBITDA is over 40% higher versus Q2 2019.”

Second Quarter and Year-to-Date 2021 Stagwell Marketing Group Standalone Financial Results

GAAP revenue for the second quarter of 2021 increased $47.2 million, or 29.1%, to $209.6 million. This included organic revenue growth of $38.7 million, or 23.8%. Inorganic revenue was $7.5 million and we reported a foreign exchange impact on GAAP revenue of approximately $1.0 million. Our GAAP revenue includes third-party direct costs, which are expenses incurred with third-party vendors when Stagwell acts as the principal when performing services for its clients. Third-party direct costs were $27.7 million as compared to $32.0 million for the second quarter of 2020, which represents a decrease of 13.3%.

Net revenue for the second quarter of 2021, after deducting third-party direct costs, was $181.8 million compared to $130.4 million for the same period in 2020. This represents an increase of $51.5 million or 39.5%. This included organic revenue growth of $43.0 million, or 33.0%. The organic revenue increase was primarily attributable to double-digit organic growth across nearly all non-political segments. Inorganic revenue of $7.5 million included acquisitions that expanded our digital transformation and digital platform management offerings. We also recorded a foreign exchange impact on net revenue of $1.0 million.

Net income for the second quarter of 2021 was $18.7 million as compared to net income of $4.8 million in the second quarter of 2020, an increase of $13.8 million, or 285.1%. Our operating expenses increased $30.5 million, which related to additional people and client delivery expenses incurred in support of the revenue growth noted above plus additional costs connected to acquired brands. Additionally, general expenses increased $11.4 million across a number of brands and our non-operating expenses increased by $2.9 million, which primarily related to increased provision for income taxes.

Adjusted EBITDA for the second quarter of 2021 was $38.7 million compared to $20.2 million in the second quarter of 2020, an increase of $18.5 million, or 91.5%. The increase was driven by the strong revenue performance that was partially offset by the increase in operating expenses noted above. Our Adjusted EBITDA margin was 18.5% on GAAP revenue and 21.3% on net revenue, up from 12.5% and 15.5% respectively in the second quarter of 2020.

GAAP revenue for the first six months of 2021 increased $43.9 million, or 12.7%, to $390.8 million. This included organic revenue growth of $25.9 million, or 7.5%. Inorganic revenue was $17.1 million, and we recorded a foreign exchange impact on GAAP revenue of $0.9 million. The organic revenue growth was primarily attributable to a $26.2 million increase in organic revenues from our Digital – Marketing segment that were partially offset by an organic revenue decline of $18.6 million from our Communications, Public Affairs and Advocacy and Digital – Content segments. All remaining segments reported organic revenue growth of $18.4 million. Inorganic revenue totaled $17.1 million and included $15.0 million from investments that expanded our digital transformation offerings and $2.2 million from investments that expanded our strategic corporate communications offering. Third-party direct costs were $50.9 million as compared to $65.7 million for the first six months of 2020, which represents a decrease of 22.5%.

Net revenue for the first six months of 2021, after deducting third-party direct costs, was $339.9 million as compared to $281.2 million for the first six months of 2020, which represents an increase of $58.7 million or 20.9%. This included organic revenue growth of $40.8 million, or 14.5%. All segments except for Digital – Content, which remained impacted by travel restrictions put in place in response to COVID, reported double digit organic growth. Inorganic revenue was $17.1 million and included $15.0 million from investments that expanded our digital transformation offerings and $2.1 million from investments that expanded our strategic corporate communications offering. We also recorded a foreign exchange impact on net revenue of $0.9 million.

Net income for the first six months of 2021 was $23.3 million as compared to net income of $17.3 million in the first six months of 2020, an increase of $5.9 million, or 34.2%. Our operating expenses increased $31.9 million, which related to additional operating expenses incurred by our existing brands in support of the revenue growth noted above plus additional costs connected to acquired brands. General expenses increased $20.4 million across several brands and our non-operating expenses (net of other income) increased by $6.1 million, which primarily related to increased provision for income taxes of 3.4 million and a decrease in other income reported in prior period not repeated in the current period of $2.2 million.

Adjusted EBITDA for the first six months of 2021 was $62.6 million as compared to $41.8 million in the first six months of 2020, an increase of $20.7 million, or 49.5%. Again, the increase was driven by the strong revenue performance that was partially offset by the increase in operating expenses noted above. In addition, the adjusted EBITDA margin was 16.0% on GAAP revenue and 18.4% on net revenue, up from 12.1% and 14.9% respectively in the first six months of 2020.

Stagwell Inc. Conference Call

Management will host a video webcast and conference call on Wednesday, August 4, 2021, at 8:30 a.m. (ET) to discuss standalone results for Stagwell Marketing Group LLC and MDC Partners Inc. for the three and six months ended June 30, 2021.The video webcast will be accessible at https://kvgo.com/openexchange-inc/mdca-stagwell-earnings-call. An investor presentation has been posted on our website at www.stagwellglobal.com and may be referred to during the conference call.

A recording of the conference call will be accessible one hour after the call and available for ninety days at www.stagwellglobal.com.

About Stagwell Marketing Group

The Stagwell Marketing Group is the first and only independent, digital-first, and fully-integrated organization of size & scale servicing brands across the continuum of marketing services. Collaborative by design, Stagwell is not weighed down by legacy points of view and its people are united in their desire to innovate, evolve, grow and deliver superior results for their clients. Stagwell’s high growth brands include experts in four categories: digital transformation and marketing, research and insights, marketing communications, and content and media. Stagwell Media LP (“Stagwell Media), is a private equity fund that owns all interests in Stagwell Marketing Group LLC through a wholly owned holding company named Stagwell Marketing Group Holdings LLC. Stagwell Media, Stagwell Marketing Group LLC and its businesses are managed by The Stagwell Group, a registered investment advisor. The address of Stagwell is 1808 Eye Street, Floor 6, Washington, D.C., 20006.

As of the date hereof, Stagwell Agency Holdings and its affiliates, including Stagwell Media, and joint actors beneficially own 50,000 Series 6 preferred shares (representing 100% of the outstanding Series 6 preferred shares), 14,425,714 Class A common shares (representing 18.7% of the outstanding Class A common shares) and 179,970,051 voting-only Class C common shares (representing 100% of the outstanding voting-only Class C common shares) of Stagwell Inc., collectively representing 75.6% of the issued and outstanding voting shares of Stagwell Inc., as calculated on an as-converted basis.

Non-GAAP Financial Measures

Stagwell has included in this press release certain financial results that the Securities and Exchange Commission defines as "non-GAAP financial measures." Management believes that such non-GAAP financial measures, when read in conjunction with the Company's reported results, can provide useful supplemental information for investors analyzing period to period comparisons of the Company's results. Such non-GAAP financial measures include the following:

Net Revenue: “Net Revenue” is GAAP Revenue adjusted to exclude certain third-party direct costs when the Company acts as principal for the services rendered in the client arrangement.

Inorganic Revenue: “Inorganic Revenue” consists of (i) for acquisitions during the current year, the revenue effect from such acquisitions as if the acquisition had been owned during the equivalent period in the prior year and (ii) for acquisitions during the previous year, the revenue effect from such acquisitions as if they had been owned during that entire year (or same period as the current reportable period), taking into account their respective pre-acquisition revenues for the applicable periods.

Organic Revenue: Organic revenue is calculated by subtracting both the foreign exchange and acquisition (disposition) components from total revenue. “Organic revenue growth” and “organic revenue decline” refers to the positive or negative changes in revenue that were not attributable to the effects of foreign exchange or acquired run rate revenue from acquisitions. The organic revenue growth (decline) component reflects the constant currency impact of (a) the change in revenue of the Company’s Brands that have been held throughout each of the comparable periods presented, and (b) inorganic revenue.

Adjusted EBITDA: Adjusted EBITDA is a non-GAAP financial measure that represents net income adjusted for (a) interest expense, (b) provision for income taxes, (c) depreciation and amortization expense, (d) other income (expenses), (e) equity in earnings (losses) of unconsolidated affiliates, (f) deferred acquisition consideration adjustments, and (g) other items, net. Other items, net includes items such as acquisition-related expenses, other non-recurring items and other restructuring costs.

Included in the Company’s press release and supplemental management presentation are tables reconciling Stagwell’s GAAP results to arrive at certain of these non-GAAP financial measures.

This press release contains forward-looking statements. Statements in this press release that are not historical facts, including without limitation the information under the heading "Financial Outlook" and statements about the Company’s beliefs and expectations, earnings (loss) guidance, recent business and economic trends, potential acquisitions, and estimates of amounts for redeemable noncontrolling interests and deferred acquisition consideration, constitute forward-looking statements. Words such as “estimates”, “expects”, “contemplates”, “will”, “anticipates”, “projects”, “plans”, “intends”, “believes”, “forecasts”, “may”, “should”, and variations of such words or similar expressions are intended to identify forward-looking statements. These statements are based on current plans, estimates and projections, and are subject to change based on a number of factors, including those outlined in this section. Forward-looking statements speak only as of the date they are made, and the Company undertakes no obligation to update publicly any of them in light of new information or future events, if any.

Forward-looking statements involve inherent risks and uncertainties. A number of important factors could cause actual results to differ materially from those contained in any forward-looking statements. Such risk factors include, but are not limited to, the following:

Investors should carefully consider these risk factors, other risk factors described herein, and the additional risk factors outlined in more detail in MDC’s initial Form S-4, filed with the Securities and Exchange Commission (the “SEC”) on February 8, 2021, Amendment No.1 filed on March 29, 2021, Amendment No.2 filed on April 22, 2021, Amendment No.3 filed on April 30, 2021, and the Prospectus Supplement filed July 8, 2021, all of which are accessible on the SEC’s website at www.sec.gov.

Note: Actuals may not foot due to rounding.

Note: Actuals may not foot due to rounding.