Just because your friend has 3,000 people on his friends list doesn't mean he speaks to all of them or knows all of them in real life. I bet there are only 5-10 people on his friends list that he actually knows in real life. The rest are people he probably just added randomly so he could look popular.
I have dated girls from myspace in the past and it isn't something I would recommend. The last time I went out with a chick from myspace, she told me she had a boyfriend when we were having dinner when her profile said she was single, which tells me she was trying to hook up with other guys on myspace behind her boyfriend's back. I'm glad she is not my girlfriend because she seems to be the unfaithful type. As far as other dating sites go, give them a try. There are still plenty of people out there your age just looking to have some fun, but are not quite ready to settle down yet.