Web 2.0 Sites Make up 12% of Web traffic, up from 2% two years ago, says HitwiseHeather Green
Hitwise put out some new data today showing that Web 2.0 sites (I didn't use the term so don't throw things at me) make up 12% of Web traffic, up from 2% two years ago. Here's a link to the PDF of a full presentation. Download file
...they also had some interesting data on participation rates at popular sites that backs up, yet again, the point that only a small percentage of folks actually are participating.
The researcher also points to Yelp, StumbleUpon, imeem, Veoh, WeeWorld and Piczo as the next potential breakout Web 2.0 sites.