Social networking sites

How much do you really know about the social networking sites that you use on a daily basis. I realized by reading this paper that I didn't know too much.

Youtube was founded in February 2005, it is currently the leader in online video sharing. Youtube makes it very easy for people to upload and share their personal videos and watch other what other people have uploaded. Many social networking websites get their revenue by selling advertising space. With the popularity rising, social networking sites can charge companies the maximum price to advertise on the homepage. The companies can advertise by using banners and text that millions of people will view daily. One of the most popular social networking sites is Myspace, who has over 168,000,000 members as of April 2007.