It was on this day nine years ago that Facebook first went online. The social network, created by Mark Zuckerberg and four friends - Dustin Moskovitz, Eduardo Saverin, Andrew McCollum and Chris Hughes - during their time at Harvard University is now a global phenomenon with more than 1 billion members.

The service was the successor to another site called Facemash which was similar to Hot or Not, a popular site at the time that asked users to vote on whether or not someone was attractive based on their photo. Facebook was initially known as "Thefacebook" and was limited to students on the Harvard campus. According to reports, more than half of the undergraduate population at the school had signed up to use it within the first month.

From there, the service spread across college campuses like wildfire. Ivy League schools like Boston University, New York University, Standord, Columbia and Yale were among the first to adopt the new service but eventually, most universities in the US and Canada had their own network.

The company was incorporated in mid-2004 and moved to Palo Alto, California. A year later, Zuckerberg dropped "the" from the name after purchasing the domain for $200,000.

The service has continued to expand ever since, filing an IPO close to a year ago and surpassing the 1 billion user mark in September 2012. The sky is seemingly the limit for Facebook as Zuckerberg and company continue to transform the service into a "mobile company" in an effort to maximize profits for shareholders.