I have been curious as to how rules on in app purchases would be enforced. If I were developing an app that supplements some form of service, I'd have *zero intention* of integrating with IAP. Technically its another code path to maintain that duplicates shit elsewhere, and needs to be integrated with existing infrastructure. From a business viewpoint its that additional engineering time, another source of financial transactions to monitor, and a 30% tax for the pleasure of it. ... Or am I missing something?

Apples rules are that if you offer an upgrade path outside of the app it must be inside the app as well. It is clear, WordPress tried to subvert this, and they got bitten. Too damn bad.