PornPal
Webcomicsnation, where I’m having Deputised Experts hosted, takes payments for subscriptions using PayPal. However, PayPal has become all coy and doesn’t want to handle accounts for anything containing adult material. So there will also be AdultWebcomics, which will use a different billing solution. It won’t be the Google wallet, because that doesn’t exist yet, but other adult industry types are looking forward to its arrival.