Why do companies advertise on social networking sites?

[Elie Love]

Can anybody tell me why do companies advertise on social networking sites such as facebook and myspace.

Thanks

[MatthewO]

To grab new customers. A site like overstock.com was relatively unknown 2-3 years ago, they struck a partnership with mypoints.com a quasi social site and by offering points and discounts through mypoints they gained new users and popularity. Another interesting reason is that individuals spend less time on TV and more time on the internet, specifically on social websites. It pays more for a company like Nike or Levi jeans to advertise on myspace or facebook than on TV. Also by having profiles on twitter , facebook or myspace companies are in a sense reaching out directly to their customer bases. Why wait for John to Google me when I can put an ad on his home page that takes him directly to my website?