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 Why Madison Avenue Should Be Wary of the Facebook-Atlas Combo Beware the Ad Servers That Are Also Media Sellers By Darren Herman, Published on March 07, 2013 2 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.