Facebook: 250 Million Users. If Only We Could Monetize Them…

In August 2008, Facebook claimed 100 million monthly active users worldwide. By April 2009, the social-networking outfit doubled that number. Today, Facebook tells us it has reached 250 million monthly active users.

Fifty million new users in under four months: Impressive.

“For us, growing to 250 million users isn’t just an impressive number; it is a mark of how many personal connections all of you have made, and how far we at Facebook have to go to extend the power of connection to the billions of people around the world,” CEO Mark Zuckerberg wrote in a post to the company blog.

If Facebook is able to maintain its growth, it will easily hit 300 million users before the end of the year, perhaps as early as November. And as a recent study from Nielsen Online found, users are spending increasingly more time on the site. Americans spent an average of four hours, 39 minutes and 33 seconds on the site in June–significantly more than any other Web site.

Clearly, Facebook is a lot more than “the flavor of the month,” as News Corp. (NWS) chairman and owner of rival MySpace (and this site) Rupert Murdoch once called it. But how long before it’s able to turn its popularity into profit befitting its user base?