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 Publicis Omnicom Group: All the Facts You Need to Know Our Handy Reference Sheet Outlines Merged Company By Rupal Parekh and Bradley Johnson, Published on July 28, 2013 18 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. Register Now Already a member? Log in.