[srwh]

You can't compare (or compare in an unfavorable way) the fundamentals of these companies with the fundamentals of hyped web companies, also many of those companies were profitable quickly and follow the IPO way. FourSquare will be here in ten years? Twitter? Zynga? M&A can make them durable but IMHO their fundamentals are more volatile: Google is not just a company who configured open source software and develop some scripts, some of their processes (adwords) can't be even copied with virtually infinite money (microsoft=>adcenter, yahoo=>overture, Apple=>iAds). We can argue that you can't copy/trash the network effect of facebook but we are in the prehistoric moments of the hypercompetitive web and their fundamentals are more volatile.