Didn't Apple change the rules about external accounts and subscriptions a couple years back? I thought you could create an app that required an external account (and external purchases) as long as there was no links to the external site from the app and no mention of subscription or external purchases within the app.
Netflix, Hulu, Spotify, and a few others have been doing it this way for a while, so I'm surprised this is news.
Audible.com is a clear example of this. All purchases have to be made on their website. The app is just a player with the ability to browse and put content on your wish list but nothing more. It's a horrible user experience but a 30% price hike on content might make me think twice about impulse purchases
Netflix, Hulu, Spotify, and a few others have been doing it this way for a while, so I'm surprised this is news.