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 Martin Sorrell to Analysts on Publicis Omnicom Merger: 'Where's the Beef?' WPP CEO Borrows Wendy's Slogan to Attack Rivals on Subject of Big Data By Emma Hall, Published on August 29, 2013 5 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.