You could imagine that currently there are more than 500,000,000+ users on Facebook. So, if Facebook were a country, it could be the third country with the most population in the world after China and India. Nowadays, the value of Facebook is more than billion.
You may not know that Facebook is a place for apps developer to make money. Currently, there are million app developers and more than 550,000+ apps are used on Facebook. Some top popular Facebook apps are Zynga, Rock You!, Electric Arts, CrowdStar, Playdom, Causes, Slide, 6 Waves, Topzy, iLike, MindJolt, RIM, etc. Among them, Zynga, the top game app developer, made $250 million in the year 2009, more than Facebook itself made in term of net profit.
Facebook also allows its users to create Facebook pages. With more than 1,500,000 active pages on Facebook, there are many popular celebrity Facebook pages. The average value of one fan could worth $136.38. Facebook also make a lot of money that in quarter 1 of year 2010, 176 billion display advertisements were posted on Facebook.
Infographic below shows the illustration of The Facebook Economy: