You’ve read all of your free items this month. To register, get added benefits and unlimited access to articles, Become a Member. Already a Member? Sign in. Advertising Age Article Abstract Facebook Forms 'Client Council' to Advise the Social Network on Advertising McCann Worldgroup's Nick Brien and Coke's Wendy Clark to Serve on Formal Group By Irina Slutsky, Published on June 22, 2011 1 Want more Access, Content & Connections? Upgrade to Membership. We are glad you are enjoying Advertising Age. To get uninterrupted access and additional benefits, become a member today. Become a Member Already a member? Log in.