40M U.S. mobile users access social nets every day

Computerworld - There's a good chance that if you didn't access Facebook or Twitter last year, you do today.

The number of Americans who log in to their favorite social networking sites has grown by 37% over the past year, according to a study released today from comScore, an online traffic tracker. In August alone, 72.2 million Americans accessed social networking sites or blogs on their mobile device.

"Social media is one of the most popular and fastest growing mobile activities, reaching nearly one-third of all U.S. mobile users," said Mark Donovan, comScore senior vice president for mobile, in a statement. "This behavior is even more prevalent among smartphone owners with three in five accessing social media each month, highlighting the importance of apps and the enhanced functionality of smartphones to social media usage on mobile devices."

According to comScore, nearly 40 million U.S. mobile phone users, which accounts for more than half of the mobile social media audience, use social sites while on the go nearly every day. As a result, mobile devices are an increasingly important part of the burgeoning social media market.

Last week, research firm Gartner reported that social media revenue is expected to grow 41.4%, from $7.3 billion in revenue in 2010 to $10.3 billion by the end of this year. That growth is expected to continue, with Gartner estimating it will reach $14.9 billion revenue in 2012 and doubling to $29.1 billion in 2015.

Facebook, Twitter and LinkedIn, three of the powerhouses of the social networking world, each saw the number of their mobile users grow by at least 50% in the past year, comScore reported.

As the world's largest social networking site, it was no surprise that Facebook had the largest mobile audience, with more than 57 million mobile users in August. That's up 50% from the previous year, noted comScore.

Twitter's mobile audience jumped by a whopping 75% to reach 13.4 million. LinkedIn's mobile audience climbed 69% to hit 5.5 million.

There are no figures available for Google+, which didn't launch until this summer.

Sharon Gaudin covers the Internet and Web 2.0, emerging technologies, and desktop and laptop chips for Computerworld. Follow Sharon on Twitter at @sgaudin or subscribe to Sharon's RSS feed . Her e-mail address is sgaudin@computerworld.com.

Read more about Web 2.0 and Web Apps in Computerworld's Web 2.0 and Web Apps Topic Center.