The results of a new study into mobile Internet usage shows that the number of Americans who are accessing social networking services and blogs using their mobile device has risen by 37 percent over a 1-year period. It was also discovered that Facebook has 57.3 million mobile users in the U.S.

According to comScore, which carried out a study on data from the comScore MobiLens service, 72.3 million people in the U.S. accessed social networks and blogs on their mobile devices in August, up from 52.7 million in August 2010. Almost 40 million people, over half of the U.S. mobile social media audience, access social networks and blogs on their mobile devices almost every day, which underscores how social media is playing an increasingly integral part in the lives of millions of people.

What’s especially interesting here is that, while the number of people who are accessing these services from a mobile Web browser has risen considerably, the number of people using apps to access social networks has grown 5 times faster over the last year. The number of those using mobile browsers to access social networks grew by 24 percent to 42.3 million, while the number of those using mobile social networking apps rose 126 percent to 38.5 million.

When looking at the audience increase for 3 major social networks — Facebook, Twitter and LinkedIn — it is revealed that their mobile audience each grew at least by half from August 2010 to August 2011. Facebook had the largest mobile audience of any social network as of August, with 57.3 million mobile users in the U.S., an increase of 50 percent from the previous year. The Twitter audience rose 75 percent to 13.4 million, while the LinkedIn audience rose 69 percent to 5.5 million (note that these figures relate to both mobile Web browser and app access to these services). It’s also worth noting that many people use third-party apps to access these services, so the actual number of people using them from mobile devices may be far higher.

Meanwhile, comScore found that around 69.5 percent of people who use social networks on their mobile devices had posted a status update, tweet or other form of update to a network from their mobile device, while 80.3 percent read posts from people they personally know.

More than half (52.9 percent) of mobile social networkers viewed content posted by brands, organizations and events on their mobile device; a third received a coupon, offer or a daily deal; and 27.7 percent clicked on an ad while browsing a social networking website.