New York—Social networking sites collectively grew 47% in April year over year, according to a study published Friday by market research firm Nielsen//NetRatings.
The top 10 networking sites, measured at home and at work, grew to an unduplicated unique audience of 68.8 million users last month, compared with 46.8 million in April 2005. Nielsen//NetRatings said the sites collectively reached 45% of so-called active Web users.
MySpace, a popular site for teens, topped the list with 38.4 million unique visitors. Blogger came in second with 18.5 million unique visitors, followed by Classmates Online, which had 12.9 million unique visitors. YouTube and MSN Groups rounded out the top five, with 12.5 million and 10.6 million unique visitors, respectively.