Does Facebook Have 600 Million Users Yet?

What’s the next big Facebook public user-count milestone?

The social networking giant had for a while publicly announced every 50 million active users it had added, though more recently it waited for 100 million increments.

If Facebook were growing purely linearly (which of course it’s not), the site would be crossing 600 million users right about now, at the turn of the year. (See the chart below, which illustrates user-count milestones since mid-2008. Facebook counts users as “active” if they have returned to the site within the past 30 days.)

CEO Mark Zuckerberg said in June at Cannes that it’s “almost a guarantee” Facebook will reach one billion users, though he didn’t predict when that would happen.

Facebook insiders said the company is waiting for a bigger milestone than just a few more million users.

A spokesperson did not suggest when that next milestone might be, saying only, “We update our stats occasionally, but have not updated our active user number since this summer when we announced that we hit 500 million people.”

Without public figures, it is of course possible that Facebook active user growth has slowed. However, just last week comScore numbers indicated that Facebook had surpassed Yahoo to become the third-most-visited Web site in the world, after Google and Microsoft.

To quote the great Justin Timberlake (sort of): You know what’s cooler than a million users? A billion users.