Facebook has just hit the 100 million mark on mobile. Facebook’s mobile user base has almost doubled in less than six months, as it had around 65 million mobile users in Sep, 2009. Facebook has been adding mobile users much faster than it is adding web users. Facebook had around 300 million users in Sep, 2009 – which has increased to 400 million users – an increase of 25%. However, the mobile user base has increased by almost 53% in the same time period.
And this pace is just going to pick up as there are more than 4 billion mobile users out there.