The number of people accessing social media through mobile devices is booming, according to comScore, which just released a report titled "The State of the U.S. Mobile Advertising Industry and What Lies Ahead." The report includes a comparison of the top 10 categories of mobile activity in March 2010 and March 2011, and the biggest year-over-year increase -- both in terms of actual users and percentage growth -- was in mobile social networking.
The number of people accessing social networks via mobile devices in the U.S. increased from just over 40 million in March 2010 to around 60 million in March 2011, for a percentage increase of 45.7%. That's even bigger than the increase in high-demand categories like weather, which grew 40.2% to just over 60 million, and personal email, which grew 30.7% to 70 million. Mobile search increased 32.1% to around 55 million, mobile news increased 38.1% to 45 million, and mobile maps increased 43.3% to 45 million.
Interestingly, location-based social networks remain a pretty small part of the mobile universe, judging by separate comScore figures showing the top seven categories for location-based mobile activity. These run the gamut from weather, the most popular with 27.8% of the market, to search with 23.3%, to maps with 19.3%, to movie information with 12%, to restaurant information with 11%, to traffic reports with 8.9%, to travel services with 5%. Assuming that location-based networks (of the sort which invite users to "check-in" via mobile) aren't folded into any of the above categories for some reason, it looks like they don't even make the cut.
The evidence does seem to suggest that location-based social networks have remained a relatively niche market, at least so far. For example Foursquare has grown from 1.8 million users in June 2010 to about ten million users worldwide nowadays -- a big proportional increase, but still fairly small relative to the Facebooks and Twitters of the world.