I’m posting this here because it took me far too long to find this information and it should be a easy to find online:
It’s actually quite simple:
· If you are selling an item that is used within your app, then you must use Apple’s in-app purchase mechanism and they receive 30% of the sale. For example: If your app is a game and you are selling extra levels for that game, then you must use Apple’s in-app payment mechanism, or your app will be rejected.
· If you are selling something that will be used outside of your app then you are perfectly free to use your own (or a third party) in-app payment mechanism and you do not have to pay Apple 30% of your sale. For example: The app I’m building will allow people to buy weekend breaks at fancy hotels, so I’m free to use my own in-app payment mechanism.
By the way, if your app is selling another app (Think of those games that try to sell you another game when you launch them), then you have to use the App store.