X0306 4 2016-01-29 0 0001158172 COMSCORE, INC. SCOR 0000806968 WPP plc 27 FARM STREET LONDON X0 W1J 5RJ UNITED KINGDOM 0 0 1 0 0001626653 WPP Luxembourg Gamma Three S.a.r.l. 124 BOULEVARD DE LA PETRUSSE LUXEMBOURG N4 L-2330 LUXEMBOURG 0 0 1 0 0001636586 Cavendish Square Holding B.V. LAAN OP ZUID 167 3072 DB ROTTERDAM P7 NETHERLANDS 0 0 1 0 Common Stock 2016-01-29 4 J 0 3493572 A 3493572 I See Footnote Common Stock 7021124 I See Footnote These shares were received upon the completion of, and as a result of the merger of Rentrak Corporation ("Rentrak") into Rum Acquisition Corporation, a wholly owned subsidiary of comScore, Inc. on January 29, 2016 (the "Merger"). These shares were received in exchange for 3,037,889 shares of Rentrak common stock that WPP Luxembourg Gamma Three S.a r.l. ("Lux Gamma Three") owned immediately prior to the Merger. On the effective date of the Merger, the closing price of Rentrak's common stock was $44.47 per share. These shares are owned directly by Lux Gamma Three, which is a wholly-owned subsidiary of WPP plc that WPP plc owns indirectly through a series of intervening holding companies. WPP plc is an indirect beneficial owner of the reported securities. Lux Gamma Three disclaims beneficial ownership of these shares. These shares are owned directly by Cavendish Square Holding B.V. ("Cavendish"), which is a wholly-owned subsidiary of WPP plc that WPP plc owns indirectly through a series of intervening holding companies. WPP plc is an indirect beneficial owner of the reported securities. Cavendish disclaims beneficial ownership of these shares. WPP plc By: /s/ Paul Richardson, Global Finance Director 2016-01-29 Cavendish Square Holding B.V. By: /s/ A. Van Heulen-Mulder, Managing Director 2016-01-28 WPP Luxembourg Gamma Three S.a r.l. By: /s/ Anne Ehrismann, Manager 2016-01-29 By: /s/ Thierry Lenders, Manager 2016-01-29