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 How Publicis-Omnicom Could Make Enormous Scale Equal Data Expertise It Won't Be Easy, And Big Integration Challenge Could Actually Slow Them Down By Kate Kaye and Abbey Klaassen, Published on July 30, 2013 0 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.