In addition to the continued growth of MySpace by 51% between March and September, other social sites making big gains in share of traffic include Bolt, up 271%; Bebo, 95%; Orkut, 63%; and Gaia Online, 41%. In terms of average session time, Gaia Online ranked first at 47:01, followed by CrushSpot (30:31); MySpace (30:22); Bebo (25:39); and Tagged (20:33).

The Hitwise study also revealed the impact that social sites have had in driving traffic to other industries on the Web. Shopping and classified sites, for instance, received 2.4% of their visits directly from MySpace in September--an 83% increase since March. Other consumer-oriented industries that received traffic from MySpace in that period include telecommunications, banks, and travel.

"Social networking has become such a significant force on the Web that users are integrating it into other daily Web activities," said LeeAnn Prescott, director of research at Hitwise. "As MySpace grows, it's showing up in the upstream and downstream [traffic] of other categories that you wouldn't necessarily think would be related."

Because of the traffic they're driving to cell phone, travel and other consumer sites, "MySpace and social networking sites in general are great ad platforms for companies in those categories," said Prescott. Even industries that don't market heavily on MySpace, such as apparel and accessories, benefit from traffic coming from the site. The sites of teen-oriented brands such as American Eagle Outfitters and Hot Topic are among the most popular visited by MySpace users, according to the HitWise study.

The report also indicated the growth of photo- and video-sharing sites as key elements of the social networking ecosystem. The top photo hosting site, PhotoBucket, increased market share by 43% from March to September, while Flickr grew by 49 percent. Visits to YouTube jumped 249 percent during that period.

Slide, which lets users create slide shows of their photos and paste them on social networking sites, was the fastest-growing site in the category with a 1,300 percent gain in traffic. "Because of the synergies with MySpace and consumer generated content, these websites show strong potential as advertising platforms," stated the Hitwise report.

While YouTube continued to dominate online video, MySpace Videos grew at nearly the same rate during the six months ending September, at 253 percent. Google Video increased by 170 percent, Metacafe by 133 percent, and Yahoo Video, 13 percent.

Users also spent the most time at YouTube, at 18 minutes 33 seconds per session. Following YouTube was Metacafe (11:58); Yahoo Video (11:37); Google Video (9:09) and MySpace Videos (6:35). Despite YouTube's continued popularity, the Hitwise reported cautioned: "it remains to be seen how users' behaviors and perceptions will change based upon new product offerings and strategic shifts by YouTube and its competitors."

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