About 11.1% of all mobile users accessed a social networking site via mobile browser in January 2010, an increase of 4.6 percentage points compared to 6.5% from the same period last year, according to a new study from comScore.

The study found that 30.8% of smartphone users accessed social networking sites on their mobile browsers, an increase of 8.3 percentage points compared to 22.5% for the same period last year, while just 6.8% of feature phone users accessed social networking sites on their mobile phones.

In January 2010, 25.1 million mobile users accessed Facebook via their mobile browser, up 112% compared to 11.9 million mobile users for the same period last year. MySpace accounted for 11.4 million users, down 7% from 12.34 million users in the same period a year ago.

Twitter has experienced huge growth in both mobile and PC-based viewers, attracting 4.7 million mobile users in January, up 347% compared to 1.05 million mobile users in January 2009. These figures do not include access of the social networking services by the nearly 6 million mobile phone owners who do so exclusively through mobile applications.

Mark Donovan, senior vice president of mobile at comScore, said: “Social networking remains one of the most popular and fastest-growing behaviors on both the PC-based internet and the mobile web.

“Social media is a natural sweet spot for mobile since mobile devices are at the center of how people communicate with their circle of friends, whether by phone, text, email, or, increasingly, accessing social networking sites via a mobile browser.”