Do you have to pay for your BTC mobile wallet?

Clients can do as they please. But paywalling is suicide. Be warned.

Again. Allow user to select ad frequency. If they want no ads, let them have no ads. Your use case solved. If they want an ad every 10 posts, let user set that. Or 1 every 20. User's choice.

But you pay the user a portion of the ad revenue as incentive incentivize allow ads view ads. When you pay the user, they'll allow ads. This is 98%+ of users.

In this format, the user isn't the product. They're also the landlord. And they have full flexibility to view or decline as they wish.