The market share of April US visits to a custom category of 57 of the leading social-networking websites increased 3 percent from March - but was down 16 percent from April 2007, Hitwise reports - via MarketingCharts. MySpace.com led in traffic, receiving 73.82 percent of the market share of US visits in April.

• Facebook ranked second by the market share of visits, with 14.80 percent, followed by MyYearbook, which received 1.33 percent.
• US traffic to MySpace and Bebo, among the top 5, decreased 5 percent and 13 percent, respectively, compared with April 2007.
• MyYearbook had the largest gain in market share in April 2008, increasing 475 percent compared with April 2007.
• Facebook and BlackPlanet followed, increasing 32 and 15 percent, respectively.

New and Returning Visitors

• Among the top five social networking websites by market share, MySpace received 95 percent of its visits from returning visitors in April.
• Facebook and MyYearbook.com followed with 93 percent and 90 percent, respectively, of traffic returning from within the previous 30 days.

Time Spent on Network

• In April, the average time spent among all social networking websites increased 73 percent compared with April 2007.
• Among the top five most-visited websites, MyYearbook led with users spending an average of 32 minutes and 54 seconds on the website.
• Facebook had the largest growth in average time spent, increasing 57 percent in April 2008, to 20 minutes and 52 seconds, from 13 minutes and 19 seconds in April 2007.

Hitwise, a subsidiary of Experian, has issued a social networking report, "The Impact of Social Networking in the US," analyzing which industries are most affected by social networks and discussing changes in audience profile of social networking websites over the last year.