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 Does Your Agency Need Its Own Trading Desk? Campbell-Mithun Says Yes Minneapolis-Based Shop Chooses Own Tech Over IPG's Cadreon By Alexandra Bruell, Published on May 15, 2013 3 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.