The barrier is what you pay for the phone, either with Apple's margins (both in the up-front cost of the phone and via the 30% paid via in-app purchases) or, on

The barrier is what you pay for the phone, either with Apple's margins (both in the up-front cost of the phone and via the 30% paid via in-app purchases) or, on Android, Google's ability to target ads at you. If consumers didn't have to pay these (arguably hidden) costs, and had to pay $1 minimum per app, then yes, it wouldn't exist or be nearly as popular.