I have loosely used the definition of Web 2.0 provided on Wikipedia, including sites that aim "to enhance creativity, information sharing, and, most notably, collaboration among users." Unsurprisingly most of these are social networks. (If I've missed any sites that should be included - let me know and I'll update the ranking).

I was a bit surprised to see how many of these sites remain independent. Facebook, Wikipedia and Craigslist are the top three that are still independent but there are lots of big community sites still up for grabs. (I should mention that Digg is not on the list because it doesn't receive enough traffic to be included among the top 20.)

There's Life Yet in Web 2.0 Sites
Visits to these Web 2 sites account for more than 1 in every 10 US Internet visits - at 10.1% of all US Internet visits in July 2008. Many of these sites are still clocking impressive growth. Looking at the top ranked sites, Facebook visits were up 23% year on year in July, YouTube up 32%, Wikipedia up 30% and Craigslist up 44%. Three of these twenty enjoyed triple digit growth: WikiAnswers up 319%, Meebo up 117% and MyYearbook up 119%.

The economy may be soft but I doubt we've heard the last of acquisition rumors in the Web 2.0 space.

Heather Hopkins

Heather Hopkins is VP of Research for Hitwise UK. This piece was originally posted on Hitwise Analyst blog here.

Image by adamconner7