Facebook Doubled U.S. Users in 2009

Facebook's great 2009 growth through its fifth year recalls that of Google, which took off and went public after its fifth year. ComScore found that Facebook more than doubled its U.S. audience from 54.5 million visitors in December 2008 to 111.9 million visitors in December 2009. The parallels are interesting but remember that Facebook is a social network and Google is a search engine, making them somewhat apples and oranges from a user experience perspective. People go to Google to search the Web. People go to Facebook to hang out with friends and even meet new people online.

News Analysis: Facebook more than doubled its U.S. audience from 54.5 million visitors in December 2008 to 111.9 million visitors in December 2009, according to researcher comScore.

The success of the social network in its fifth year is the greatest for a Web company since that of Google, which went public after its fifth year and now earns nearly 2 billion a quarter in profit.

Facebook, which continues to add new features geared to retain and grow its loyal audience past 350 million users, soaks up 7 percent of all time spent online by users in the U.S.

ComScore also found that many of Facebook's core metrics more than doubled. From December 2008 to December 2009, the site's unique visitors grew 105 percent; its page views grew 151 percent and total time spent grew 198 percent.

Other stats, such as average minutes per usage day and average usage days per visitors grew more modestly, at 6 percent and 37 percent, respectively.

Facebook did see its the average minutes per visit drop 11 percent, to which comScore noted makes sense when one considers the increasing frequency with which people are coming back to the social network. See comScores' full stats in full here.

ComScore Director of Industry Analysis Andrew Lipsman said the great growth spurts validate Facebook Founder and CEO Mark Zuckerberg's Law, in which the amount of information people share doubles ever year.

""In other words, once the network is in place and people are active and engaged, the dynamics of the social interaction taking place incentivize participants to share information about themselves more regularly, which in turn solicits more engagement from others, creating a virtuous cycle of interaction," Lipsman noted."

What is perhaps astounding about the growth is that Facebook only opened registration to the masses a few years ago. Zuckerberg launched the company from his Harvard University dorm room in February 2004, but it wasn't until the fall of 2006 that Facebook became available to the general public. Facebook is just shy of its sixth birthday (Feb. 4).

With that level set, the company's meteroric growth is comparable to and in some ways better than that of Google, with whom it is vying for peoples' attention on the Web.

Google took off incredibly after its fifth birthday, and debuted on the stock market in August 2004, almost six years after Google co-founders Larry Page and Sergey Brin launched it from Stanford University.