MEMBERSHIP INTEREST PURCHASE AGREEMENT

This MEMBERSHIP INTEREST PURCHASE AGREEMENT, dated November 10, 2008 (this “ Agreement ”), is made by and among MDC Acquisition Inc ., a Delaware corporation (“ MDC Sub ”); CPB Acquisition Inc ., a Delaware Corporation (“ Acquisition Co. ”); MDC Partners Inc ., a Canadian corporation (“ MDC Partners ”); Crispin & Porter Advertising, Inc. (d/b/a Crispin Porter & Bogusky), a Florida corporation (“ CPB Inc. ” or “ Seller ”); Charles Porter (“ Porter ”), Alex Bogusky (“ Bogusky ”), Jeff Hicks  (“ Hicks ”), and Jeff Steinhour (“ Steinhour ”; together with Porter, Bogusky and Hicks collectively referred to as the “ Employee Members ” and individually as an “ Employee Member ”); MDC Sub, together with the Acquisition Co., Employee Members and CPB Inc., collectively referred to as the “ Members ” and individually a “ Member ”);   and CRISPIN PORTER & BOGUSKY LLC ,   a Delaware limited liability company (the “ Company ”).  Capitalized terms used herein and not otherwise defined shall have the meanings ascribed to such terms in the Company’s Amended and Restated Limited Liability Company Agreement dated as of January 8, 2001 (as subsequently amended, the “ LLC Agreement ”).

WHEREAS , CPB Inc., the Employee Members, MDC Sub and Acquisition Co. are parties to that certain LLC Agreement of the Company, which sets forth, among other things, the terms and conditions relating to transfer and ownership of the Membership Interests upon exercise of a put or call option;

WHEREAS, pursuant to the LLC Agreement, Acquisition Co. has the right to exercise the “Third Call” option, and is hereby exercising such Third Call option early, with respect to the purchase of an additional 17% of Membership Interests from CPB Inc., and has assigned such rights to exercise the Third Call to MDC Sub;

WHEREAS , CPB Inc. (the “ Seller ”) accepts MDC Sub’s early exercise of the Third Call option and now desires to sell, and MDC Sub desires to purchase, an aggregate amount equal to 17% of the issued and outstanding Membership Interests in the Company (the “ Purchased Interests ”), from the Seller;

WHEREAS , immediately following the execution and delivery of this Agreement, the parties hereto are entering into a further amendment to the LLC Agreement to reflect the transactions contemplated by this Agreement, including the transfer of the Purchased Interests to MDC Sub such that following the Closing of the transactions contemplated by this Agreement, the Membership Interests in the Company will be owned as follows:   MDC Sub – 45%; Acquisition Co. – 49% ; CPB Inc. - 6%.;

         NOW, THEREFORE , in consideration of the mutual covenants and agreements set forth in this Agreement, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties do hereby agree as follows:

            1.          Purchase and Sale; Closing .

                      (a)           Sellers hereby sell, assign, transfer and deliver to MDC Sub, and MDC Sub hereby purchases from Seller, the Purchased   Interests .    The Purchased Interests carry with it the right to share in the Profits and Losses of the Company (as such terms are defined in LLC Agreement) and the other economic attributes thereof (including distributions of Cash Flow in accordance with the LLC Agreement) accruing from and after November 10, 2008 in respect of the Purchased Interests transferred hereby, and the Seller’s rights in its Capital Account with respect to the Purchased Interests as of November 10, 2008, subject to Seller receiving distributions in the ordinary course that it would have received in respect of the Purchased Interests for the period of time ending immediately prior to the Closing Date.  For purposes of this Agreement, the calculation of “Profits and Losses” shall be done in accordance with the LLC Agreement, and shall be based upon profits, losses and distributions in accordance with the Company’s current financial and operational policies as of the Closing Date and determined in a manner substantially consistent with recent practices (e.g.,  no extraordinary dividends).

                      (b)           The closing of the transaction contemplated by this Agreement (the “ Closing” ) is taking place simultaneously with the execution and delivery of this Agreement (the “ Closing Date ”), at the offices of MDC Partners Inc., 950 Third Avenue, New York, New York 10022 or by the exchange of documents and instruments by mail, courier, telecopy and wire transfer to the extent mutually acceptable to the parties hereto.

                      (c)           Effective as of November 10, 2008, MDC Sub, Acquisition Co. and CPB Inc. shall cause the Company to close its books for income tax purposes, and there will be no allocation of Profits or Losses to Sellers with respect to the Purchased Interests following the Closing Date.  All distributions of Profits payable as of November 10, 2008 in respect of the Membership Interests (including the Purchased Interests) shall be distributed and paid by the Company in the ordinary course following the Closing.  In accordance with the LLC Agreement, the parties have agreed to elect to adopt the closing of the books method under Section 706 of the Code for allocating CPB Inc.’s varying interests in the Company during the taxable year that includes the Closing Date.

            2.          Purchase Price .  

                      (a)           In full consideration for the purchase by MDC Sub of the Purchased Interests, and in full satisfaction of any and all amounts due and owing by Acquisition Co. with respect to the Period Three Formula Amount (as such term is defined in the LLC Agreement), MDC Sub agrees to pay to Sellers an amount equal to the “ Put/Call Purchase Price ”, calculated and determined as follows:

{2.85 x average monthly “Profits” (as defined in the LLC Agreement) of the Company during the Additional Period}- $5.1 million. 

For purposes of this Agreement, the “ Additional Period ” shall be the period of time from the Closing Date to March 31, 2010.

                      (b)           For purposes of this Agreement, all of the terms, conditions and procedures set forth in Sections 10.4.2 and 10.5 of the LLC Agreement regarding “Accounting Determination” and “Payment of the Purchase Price” shall apply and govern the determination of Profits and the Period Three Formula Amount, and the payment of the Final Purchase Payment.  In the event that the Period Three Formula Amount has not been finally determined by March 31, 2010, the Final Purchase Payment to be made on April 1, 2010 shall be equal to 75% of a good faith estimate of such amount estimated by MDC Partners in its reasonable judgment (the “ Undisputed Payment ”). Upon final determination of the Period Three Formula Amount, the balance of the Final Purchase Payment shall be promptly paid to Seller. In the event that MDC Sub fails to pay the Undisputed Payment to Seller in respect of the Final Purchase Payment on or prior to April 1, 2010, and if Seller has otherwise complied in all material respects with its obligations under the LLC Agreement, then Seller shall be entitled to liquidated damages from MDC Sub in an amount equal to the Final Purchase Payment plus 17% of the Profits of the Company during the period commencing April 1, 2010 and continuing until the date on which the Undisputed Payment is paid to Seller.

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