Facebook has been around for more than six years and is the most popular social network out there. Most of my family is on FaceBook, my mother, sister's and cousins.
FarmVille and Mafia Wars. These are two of the most popular of the many free social network games that FaceBook has to offer.
How do you make money you ask? As I have mentioned before, social networks are a great way to promote your site, interacting on facebook and playing the games makes it that much easier and even more fun. As you make friends and get to know people you tell them about your blog, and of course being a social network butterfly themselves, they love the idea of chatting on other sites with their friends.