As with the FriendFinder group, MyLot is a place where I have made money, but haven't continued using it because it really wasn't for me.
MyLot is a discussion site, kind of like a forum, you start discussions, respond to discussions and upload photos. MyLot pays you for all these actions, in my case a few cents every time I did something. I think that if a discussion you started gets popular you also get payed some from the responses you get.
MyLot also has a referral system, where if you refer a sign-up you get a cut of whatever that user makes, I have referred 3 people to date, but none of them have been active.
The earning money for your contributions aspect is just a little icing on the cake, because even if you didn't have the ability to earn money it would still a very enjoyable site.