Check out this excellent post on marketing a startup by Josh Kopelman, Founder and Managing Partner at First Round Capital (one of the VCs behind Xobni).
http://redeye.firstround.com/2008/01/after-the-techc.html
His key point is that a single event (such as TechCrunch) sprinkled with viral growth should NOT define a startup’s marketing strategy. He then goes on to explain what should. His recommendations are right on the mark.