Here is an interesting idea. AT&T is working on a system were app developers can create an app that charges the developer for the data usage and not the user. It would be kind of like a 800 number for apps. So if a developer could create a streaming music service, presumably subscription based, that the user user can use all day long and not use up any of their data limits.
http://www.engadget.com/2012/02/27/atandt-app-developers-pay-for-data/


