Facebook may be the biggest social network, but it wasn't the first.
You might remember MySpace and Friendster. You may have had accounts on those sites. But when was the last time you visited them? Does anyone use those social networks anymore?
Turns out plenty of people do... if you know where to look.
MySpace: The original social network success story suffered a rapid decline in popularity as Facebook thrived. But you might be surprised to know that MySpace is still one of the most visited sites on the Internet.
According to Alexa, MySpace is ranked #155 in the world - far from Facebook's #2 ranking, but surprisingly high. And it still sees most of its traffic come from the United States.
Orkut: The name may not be as familiar, but this was Google's first attempt at a social network. It never caught on in the United States - but it did in Brazil.
Orkut is the 20th most popular site in Brazil, and takes 60% of its traffic from the country. It also has a significant following in India and Japan.
Friendster: Finally, there's Friendster, which still exists... but not in the form you remember. It's also not nearly as popular today as MySpace or Orkut, but still sees most of its visitors from south-east Asia.
But where the old Friendster functioned a lot like a basic Facebook, the new Friendster is a gaming platform. You can play a variety of web games with people online. And if you want to boast about your scores and achievements? The new Friendster offers an option to post them to... Facebook.