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 WPP's Next Dedicated Agency Prospect: Team United Independent Shop Horizon is Currently United's Media Agency By Alexandra Bruell, Published on December 06, 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.