Yesterday in the context of its mobile event Facebook announced (consistent with my prediction) that the company had more than 200 million active mobile users around the world. I earlier asked Facebook to break this out by US vs. international numbers, which they declined to do. But let's try and figure that out . . . shall we.
Facebook itself says that 70% of its usage comes from outside the US: "About 70% of Facebook users are outside the United States." That means (assuming 500 million total users) that 150 million users are in the US.
If we were to assume that mobile usage breaks down along the same US-international lines that would mean 140 million mobile users would be international, while 60 million would be in the US. My guess is that mobile usage doesn't break down along those lines exactly. Much of Facebook's mobile usage is likely to come from smartphones and its mobile apps in particular, although Facebook does operate sites for non-smartphone browsers and has a text only site at 0.facebook.com.
The US doesn't have the highest smartphone penetration among Western countries, Spain probably does. But in absolute numbers the US has more smartphones than any other country. Let's say (based on a collection of third party data points) that are something like 60 million smartphone users in the US. How many of those people are using Facebook (probably not 100%). Yet Facebook's mobile usage doesn't come exclusively from smartphones. We don't know, however, how many non-smartphone Facebook users there are in the US or elsewhere in the world.
Nielsen says there are 85 million mobile Internet users total. So one would need to assume that there aren't more US mobile Facebook users than 85 million. My guess then is that there are about 75 million mobile facebook users in the US. If we were to treat Facebook as a mobile ad network, where would 75 million users put them in the hierarchy?
According to the Nielsen data, Facebook would be the largest mobile ad network. Notwithstanding Facebook Deals, announced yesterday, it doesn't quality as a mobile ad network -- quite yet.