Facebook.com CEO Mark Zuckerberg is shown at his office in Palo Alto, Calif. Zuckerburg blogged that Facebook has reached 300 million users. (Paul Sakuma/Associated Press)

Facebook founder and CEO Mark Zuckerberg says the social networking site has more than 300 million users, and earned more money than it spent last quarter.

In a blog post on Facebook, Zuckerberg wrote that the company was "cash flow positive" in the last quarter. He had previously projected that Facebook would meet that goal in 2010.

"This is important to us because it sets Facebook up to be a strong independent service for the long term," Zuckerburg wrote.

Zuckerberg didn't go into detail about how much money the company made. It's believed Facebook makes hundreds of millions of dollars annually in advertising revenue.

The company's value has been recently estimated to be up to $10 billion US, but an internal appraisal put the market value of Facebook at $3.7 billion US.

This is the first time that the Palo Alto, Calif., company has announced making more money than it spent.

Zuckerberg also announced that Facebook has hit the 300-million user milestone.

"As of today, Facebook now serves 300 million people across the world. It's a large number, but the way we think about this is that we're just getting started on our goal of connecting everyone," he wrote on his blog.

Facebook announced that it had signed its 200 millionth user in April.