How those social networking sites are benefited?

Quest_Knowledge: How those social networking sites are benefited?
There are many social networking sites, i want to know how they are benefited? I know they are doing this for money, but how they are getting money?

Answers and Views:

Answer by a_spicer2003
Some are going commercial, most will go commercial if they haven’t already. Some have additional benefits and features for paying users. Some are probably compensated by Advertising which displays on every page that you view, including often your profile. Having a lot of eyes makes a pretty easy advertising sales. Imagine being Facebook or Myspace. Pretty much everybody and his brother and sister are on there. That’s a large advertising audience.

The rest I think are selling us down the river to the Russians or something. (Not that there is anything wrong with Russians.) That was joke ok 😉

Answer by br_an_don
They are getting tons of free content to their websites, at the same time people are posting links all over the place to their bookmarks.
I like to automate my social bookmarking with a tool called Bookmarking Demon. It’s up to almost 100 sites that it’ll submit too, I submit almost every blog post I make to all those accounts and the social bookmarking sites are getting loads and loads of traffic and free content.
If you can make a popular social bookmarking site, they will generally go viral on their own.