Of the 1.1 billion people ages 15+ worldwide who accessed the internet from a home or work location in May 2009, 734.2 million visited at least one social networking site during the month, a penetration of 65%, according to data from the comScore World Metrix service.  comScore also reported that among 40 individual countries reported by comScore, Russia has the world’s most engaged social networking audience, with the average online Russian spending 6.6 hours and viewing 1,307 pages per month.

Brazil ranked close behind Russia at 6.3 hours, followed by Canada (5.6 hours), Puerto Rico (5.3 hours) and Spain (5.3 hours).

The US ranked at #9  in terms of social network engagement, with an average of 4.2 average hours and 477 pages consumed per visitor.

“Social networking has become a popular online pastime not only in mature internet markets like North America, but also in developing, high-growth internet markets such as Russia,” said Mike Read, SVP & managing director, comScore Europe. “In a country as geographically large as Russia, social networking represents a way of connecting people from one corner of the country to the other.”

Vkontakte.ru: Russia’s Largest SocNet Site

Of the 31.9 million people who accessed the internet in Russia in April, 18.9 million visited at least one social networking site, representing a reach of 59% of the total online population. The most popular of these sites was Russian-based Vkontakte.ru with 14.3 million visitors, followed by Odnoklassniki.ru (7.8 million visitors), Mail.ru - My World (6.3 million visitors) and Fotostrana.ru (1.6 million visitors).

Facebook.com attracted 616,000 Russian visitors, up 277% vs. the same period in 2008.