This is something I had been wondering during the previous arguing around in-app purchase commissions.
Up-front app costs, in-app purchases, in-app subscriptions... they're really all the same thing. You can't charge 30% for one and not for the other... and if you allow folks to transact the purchase outside your ecosystem, you basically get nothing.
With Apple not enforcing the ability to get in-app purchases, the only thing preventing out-of-band sales is the convenience factor. What if someone just set up a fiat currency site where you could go buy credits that would then be accepted by iPhone apps? They could then be sold entirely free, but just require that you sign in with that external account so they can take some of the prepaid credit.
Up-front app costs, in-app purchases, in-app subscriptions... they're really all the same thing. You can't charge 30% for one and not for the other... and if you allow folks to transact the purchase outside your ecosystem, you basically get nothing.
With Apple not enforcing the ability to get in-app purchases, the only thing preventing out-of-band sales is the convenience factor. What if someone just set up a fiat currency site where you could go buy credits that would then be accepted by iPhone apps? They could then be sold entirely free, but just require that you sign in with that external account so they can take some of the prepaid credit.