Carl Bialik from WSJ writes "Two tech VCs, Todd Dagres and David Hornik, debate whether there is a bubble in so-called Web 2.0 companies looking to cash in on a resurgent online ad market. In the WSJ.com debate, Hornik writes: 'Venture capitalists will rationally stop investing in ideas that don't bear fruit. Those that do bear fruit will gain traction and either be acquired or go public. Those are the traits of a rational market in my mind.' Dagres responds: 'I think the Web 2.0 space will have a higher mortality rate than other segments of the overall media and technology industries. There are far too many MySpace and YouTube genetically challenged clones. All but a few will fail. The winners are generally the ones that get in early and out before the bubble bursts. There are rare examples of bubble companies making it through the bust and going on to become successful and valuable companies. By the way, the combined cash flow of Spot Runner, LinkedIn and Facebook is less than that of one Costco store.'"