[cube13]

I don't think that any of the three are willing to try to integrate billing directly instead of relying on Paypal, Visa, etc. It's a regulatory minefield between all the world governments, and the % that the payment processors take is probably very much worth the costs that would otherwise be taken from keeping such a system working.

I'm sure Apple and Google have explored it, but in the end, found that the current payment processors provide both a level of service(Visa's payment backend, as far as I can tell, has never suffered non-scheduled downtime) and help avoid all the regulatory pitfalls that it's worth the price.