Whenever you sign up with a social network you are often given a free and useful tool - The profile page, this is invaluable to you as it makes people aware of who you are, it brands your name and face to whatever you do online and off line, but for our purposes we want online to be our focus.
Social networking sites are all the rage these days, they provide ways of interacting with people who enjoy the same interests as you do, a lot of the time people are online for hours on end, each and every day, so the amount of new networking sites that keep popping up are essential to corner your affiliate niche markets online.
I recommend using your best affiliate promotions, one for each social networking site, measure the results and go from there.
A comprehensive list of social network sites I Frequent, with more to follow when I update later on - link to me if you wish!: