UGC sites rock!

User-generated content (UGC) sites--venues for photo-sharing, video-sharing, and blogging--comprised five out of the top 10 fastest growing Web brands in July 2006, according to Nielsen/NetRatings. Those sites include ImageShack (No. 4), Heavy.com (No. 5), Flickr (No. 6), MySpace (No. 9) & Wikipedia (No. 10).

In addition, Nielsen found that among the top 10 Web brands overall, MySpace was the No. 1 fastest growing. Google ranked No. 2, while eBay rounded out the top three.

However, "being popular now is not a guarantee that you'll remain on top for the long haul. " according to CNN. That's why none of those UGC sites goes public.