I have for along time thought that these "social networking" sites were garbage. I got acconts on myspace back when it was a realitlivly new thing but soon realized the stupidity of people on the site.

For example: I would get a friends request. As normal, I would check their profile before I would accept them. 75% of the time their bio would read something to the effect of "Hi, my name is _____. I love football, swimming, xbox, and shopping. I'd love to get to know you click here for free ring tones!!" You get the idea. :5
It is more of a marketing tool now. I honestly log into my myspace page just to see how long it has been since I logged in last. On average its about 5-6 months.

I got facebook when I was in college. Because you had to be in college to get it at the time, so I thought it would remove a lot of that garbage I was dealing with on Myspace. And I was right, up untill it became open to everyone.
I check my facebook every month just to keep in touch with those fuckers that are too busy to call me.

If you want to use a social networking site to the best of its abilities use a small one.
In all honesty I have made more "New contacts" on TTP than I have on Social networking sites.