most things are US-only which already kind of sucks

there’s square cash, which does a no-questions-asked money transfer with zero effort and no fees (no fucking around linking bank accounts, no balance stored in their wallet) but both parties have to have a US debit card.  otoh the money moves from bank account to bank account in like a day, and you can send money in about ten seconds by just writing an email, no login even required

square also has an invoice thing apparently, which might support international credit cards (unclear, conflicting info, lmk if you try it out), but definitely supports US credit cards

there‘s also stripe, another credit card processor thing, but i think they’re more about integration than about making it easy for individuals to move money around.  also i think they have explicit rules against porn, though i’ve never heard of them being enforced against artists.

other things i have heard of:

• dwolla (US only, requires linking a bank account and not just a credit card, has its own balance like paypal, flat fee of 25¢)
• venmo (US only i think, don’t really know much else about it but people always bring it up when i complain about paypal)