Something like this?

http://pledgex.net/

I'm pretty sure there are camgirls who take payment directly, not even including GirlsGoneBitcoin. But the ones I know personally were working more or less as employees of a middleman.

Some performers do use Patreon. But if you want to promote your erotic work, Patreon doesn't accept accounts promoting porn with live actors, only drawn art.

So there's a huge gap in the market for a nsfw patreon? (Porntreon?)

oh yeah, lots of creators use Patreon. Fenoxo, the creator of the text based RPG Trials in Tainted Space (he sells it in MiKandi), uses Patreon and brings in $20K a month. https://www.patreon.com/user?u=121401&u=121401&ty=h

So far it's a great service for adult art and fiction creators. But as with any mainstream service and adult content, you can't ever be sure how long it'll last. Past experience has shown it's a matter of time before adult gets kicked out of the party. I hope that won't be the case with Patreon.

There are quite a few people on reddit doing direct business