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 Google Wallet's Killer App: Subway, Macy's and Major Retailers Payment Platform Also Partners With Citi MasterCard; Will Be Tied to Newly Launched Daily-Deals Service Offers By Kunur Patel, Published on May 26, 2011 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.