Facebook announced new usage milestones in its S-1 filing today: 845 million monthly active users including 425 million users who access the service on mobile devices.
The company had last claimed 800 million monthly active users and 350 million mobile monthly active users at its f8 developer conference in September.
Overall, that means the social network has seen a 39 percent increase in monthly active users since December 2010. It saw particularly strong growth in Brazil with a 268 percent increase year-over-year and India with a 132 percent increase. Notably, both of these markets were strongholds for Orkut, an early rival social networking service from Google.
In the U.S., Facebook is starting to hit its saturation point with 161 million monthly active users, a 16 percent increase from the previous year.
It comes as little surprise that a large percentage of users return regularly. Facebook has long said that half of its users access the site daily. The social network had 483 million daily active users in December 2011, an 48 percent increase since December 2010. According to the company’s IPO filing today, 360 million users were active on at least six days a week in December 2011.
Of course, the larger Facebook gets, the harder it may be for it to grow. “We anticipate that our active user growth rate will decline over time as the size of our active user base increases, and as we achieve higher market penetration rates,” the company said in its filing today. “To the extent our active user growth rate slows, our business performance will become increasingly dependent on our ability to increase levels of user engagement in current and new markets.”
One of the last bastions where Facebook might find an additional 500 million or more users is in China — a country it has explored but never formally entered. In addition to government censorship, it would find many mature rivals there including Sina and Tencent. Prospects there do not look promising, especially considering that Google lost substantial search market share there after a disagreement with the Chinese government. “We do not know if we will be able to find an approach to managing content and information that will be acceptable to us and to the Chinese government,” the company’s statement said.
The company defines active user as a registered user who has logged in and visited Facebook through a website or mobile device in the last 30 days. Facebook also shared stats about activity on its platform. As of December 31, 2011, there were more than 37 million pages with ten or more Likes. More than seven million apps and websites have integrated with Facebook.