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 Brands Bet Millions That Apple's iTunes Radio Scales Quickly Apple's Device and OS Infrastructure Gives it Chance to Be the Biggest By John McDermott, Published on September 18, 2013 4 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.