I use Facebook, both for business and personal. It actually is a great tool for brand development.
If you have a business it's a great place to network and communicate with the right audiences. You know there are groups related to adult subjects on there.

I also use Twitter, though again this isn't so much about creating sales it's about being connected and brand awareness. Only just started this though so I don't really know too much about it.

Interesting perspective here:
In my regular employment we don't have access to email. When Clients call me asking for something to be done I have to ask for a fax, and they ask "can't I email it to you". It makes us look backward and severely behind the times. I hate it but my direct manager is a retard.

Twitter and FB are like this. If you have a site and you don't have Twitter and FB functionality visible for your customers they'll think of you as backward.

It's easy to do an it's actually pretty easy to maintain. Takes a few minutes a day.

For the sake of five minutes on line on FB and a few texts or tweets, you are able to connect with millions of people. That cannot be a bad thing.

I'm also a member of the B8M8 Network, that's an adult male community dedicated to masturbation. So it's perfect fit for my business. I help them out with content and special offers, and they help me out with advertising to their customers. I effectively gained 1200 newsletter subscribers (and growing) for doing very little.