Facebook’s S-1 Reveals: 845 Million Users Every Month, More Than Half Daily, Half Mobile

As part of its initial filing to go public, Facebook has just revealed some new user numbers that illustrate just how big it is.

It had 845 million monthly active users and 483 million daily active users as of December, for year over year growth of 39% and 48% respectively. Mobile is also now half the user base, with 425 million monthly actives. Some other stats, which are a bit more vague: 100 billion friend connections as of the end of last year, and 2.7 billion Likes and Comments per day during the last three months of the year.

All in all, this basically stacks up with what the company has previously shared. It said in September that it had some 800 million MAUs.

One other point on the numbers is that Facebook is providing a fairly extensive caveat around what it’s counting:

The numbers of monthly active users (MAUs) and daily active users (DAUs) presented in this prospectus are based on internal company data and we use these numbers in managing our business. We believe that our MAU and DAU numbers are reasonable estimates, and we take measures to improve their accuracy, such as eliminating known fictitious or duplicate accounts. There are inherent challenges in measuring usage across large online and mobile populations around the world. For example, there may be individuals who have multiple Facebook accounts in violation of our terms of service, despite our efforts to detect and suppress such behavior. As another example, applications on certain mobile devices may automatically contact our servers for regular updates with no user action involved, and this activity may cause our system to count the user associated with such a device as an active user of Facebook. We estimate that less than 5% of our estimate of worldwide DAUs as of December 31, 2011 could have resulted from this type of automatic mobile activity and that this type of activity had an even smaller effect on our estimate of worldwide MAUs. The impact of this automatic activity on our metrics may vary by geography, as mobile usage varies in different regions of the world. In addition, our data regarding the geographic location of our users is based on a number of factors, such as IP address, which may not always accurately reflect user location. We regularly review and may adjust our processes for calculating these metrics to improve their accuracy. In addition, our MAU and DAU estimates will differ from estimates published by third parties due to differences in methodology. For example, some third parties do not count mobile users.