Facebook, the world's most popular social networking site, has turned eighth. With an estimated 845 million active subscribers, the social networking giant still continues to grow, since its launch on February 4, 2004 and is most likely to have 1 billion users by August this year. While, the company CEO Mark Zuckerberg is best known as the man who built Facebook, the company has three other co-founders, all college roommates and fellow students of Harvard University; Eduardo Saverin, Dustin Moskovitz, and Chris Hughes.

The four initially built the service exclusively for Harvard students, but it was soon expanded to other colleges and eventually added support for students at various other universities. Initially before it’s public launch, it was called 'thefacebook.com'. However, on 4th February 2008, Zuckerberg renamed to domain name and launched what we know today as 'Facebook'.
    
Facebook has not only put Mark Zuckerberg in the list of top and youngest millionaires but also helped a lot of start ups, non profits and other companies grow, interact and increase sales. In January 2009, Compete.com study ranked Facebook as the most used social networking service by worldwide monthly active users. Quantcast estimates Facebook has 138.9 million monthly unique US visitors in May 2011.  According to Social Media Today, in April 2010 an estimated 41.6 per cent of the US population had a Facebook account.
    
In India, Facebook has registered a growth of 132 per cent this year, which is higher than many other countries. In some countries, such as Turkey or Chile, up to 80 per cent of Internet users are registered with Facebook. The Russian Facebook audience exceeds 5 million people. However, company's market growth has started to stall in some regions, with the site losing 7 million active users in the United States and Canada in May 2011. The company has filed for an initial public offering (IPO) on February 1, 2012.