Founded: 2000

Estimated users: 5.9 million

Addictiveness rating: 8.5

Very popular with UK teenagers this service offers a number of features such as instant messaging and viewable profiles. Its popularity peaked between late 2004 and late 2005 and has been declining slowly since. For a fee, users over the age of 18 are able to view adult pictures posted on the site and it has signed an exclusive deal with Sony BMG for their artists to be promoted on the site and for free downloads for users.