During Facebook's first quarterly financial report, the social network is shown to sport more than half a billion monthly active users on mobile. This quarter's results showed that an astounding 543 million users use the social network from a mobile device.
This number is expanded considerably from the end of 2011, which saw 432 million mobile monthly active users, a jump of 110 million in 6 months. Since Q2 of 2010, Facebook have been adding an average of 48.5 million mobile users each quarter. As a percentage of total users, mobile users have grown from 32.2-percent of Facebook's user base, to 56.9-percent today. Quite the jump.
The problem here is, Facebook heavily relies on its revenue from advertisements, which are hard to show on mobile, and ill-suited for the platform. The smaller screens on smart devices make Facebook's ad model much less attractive for marketers. But on the desktop, its a different story. The bigger screen, higher resolution, make it much easier to display ads without distracting the user too much, on mobile though... bigger problem.