Just how fast is Facebook growing?

Facebook may have become the Internet's second most popular destination after Google, according to recent statistics. But that's if you're willing to believe that the social site is essentially acquiring a small state every day.

By any measure, the social networking site Facebook is becoming a phenomenal success. The BBC reported that it accounted for one in every 22 online visits on Christmas Day, according to Internet research company Hitwise -- up 69% from the same time in 2007 and with an overall market share of 4.65%, making it the second most popular site after search engine Google.

Then on January 7, Facebook creator and CEO Mark Zuckerberg -- the 24-year-old who is now #321 on the Forbes 400 List of Richest Americans -- posted on the official Facebook blog that the site had hit 150 million active users, almost half of whom are using it every day.

What makes this particular notable is that Facebook had just reported hitting 140 million about three weeks before -- meaning the site is gaining some 450,000 people per day, according to AllFacebook, the unofficial Facebook blog. "If the company keeps up this pace for the first half of 2009, the company will easily hit 230 million users," the blog went on. "If the pace continues the whole year, the company will surpass 300 million users."

Wow. Imagine how many mob wars, pillow fights, and nicest person requests that'll result in. It could also theoretically result in a skyrocketing of the number of examples of ignoring Facebook application requests (a group called "Ignoring Application Requests" with more than 23,000 members).

To throw some more statistics at you: If Facebook were a country, it would be the eighth most populated in the world, just ahead of Japan, Russia and Nigeria. It is used in more than 35 different languages and 170 countries and territories. In countries such as Italy, Spain, France, and Switzerland, monthly growth rates are reaching 50 percent.

What's particularly interesting is the gender demographic. Conventional wisdom is that computer geeks are male, but looking at these on the (truly awesome) demographic analyzer on the AllFacebook unofficial Facebook blog shows that in the US, for example, there's a full 5 million more female users than male.

According to Danah Boyd, in her seminal paper "Viewing American class distinctions through Facebook and MySpace," Facebook launched in 2004 as a Harvard-only site and slowly expanded to .edu accounts from different universities. In mid-2005, it opened its doors to high school students, but required an invitation, which naturally was more likely for high school students acquainted with college students.

"The message was clear: college was about Facebook," Boyd's paper said. For all of 2005 and most of 2006, "MySpace was the cool thing for high school teens and Facebook was the cool thing for college students." But then Facebook opened to everyone in September 2006, and the dam started breaking.

It's making money, too. As of September 2008, it had annual sales of $300 million (through ads, presumably) and had an estimated worth of $15 billion.

Like Meetup before it, Facebook is being used worldwide to organize protests and political movements, according to Clay Shirky in his book Here Comes Everybody. Certainly, the 2008 US political campaign and its grassroots efforts resulted in a huge number of people -- beyond just college students -- who joined the site to get involved.

And in this age of decreasing social interaction -- as described by Robert Putnam in his book Bowling Alone -- something like Facebook gives people the illusion, if not the reality, of intimacy, and an intimacy that transcends geographic boundaries.

The site is not without controversy; it is currently under fire for deleting pictures and even accounts from women who post pictures of themselves breastfeeding, and it has also come under attack for its "Beacon" data sharing program, which users called a breach of privacy.

Now, if you'll excuse me, I'm going to go post the URL for this article on Facebook, so my 449 friends will all see it.