Despite what people might say about them, I've levelled up 3 accounts with
Adult Friend Finder to over $100K+ earnings over the last few years:
There are so many others that come and go, and promise to be the next big thing, but AFF still convert very well, retain customers with their online magazine, advice section, stories, community features etc. I've tried them all on my main sites, and still push AFF more than any other.