The thing is, Apple does allow this sort of thing. Look at apps like Google Play Movies. You can't buy or rent from within the app, so google doesn't get their

The thing is, Apple does allow this sort of thing. Look at apps like Google Play Movies. You can't buy or rent from within the app, so google doesn't get their cut - you can only buy and rent from google play movies on the website, thus bypassing Apple entirely. You can then play that content within the iOS app. All in direct competition with iTunes.