I'm not sure if anyone see's this useful. Or if the price is right.
But I have an adult social network which gains almost 50 new members each month (49 in January).
I'm now selling 5 ad spots on the site for 299$ each. It's a one-time payment for 12 months of advertising.
I'll soon start advertising on multiple sites and try to gain more users in multiple ways.
Comment if you're interrested!