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 Building an Army of Hyper-Local, Mobile-Connected Advocates Or, Why Marketers Should Pay Attention to Foursquare By Allison Mooney, Published on August 05, 2009 12 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.