Is the market for IPOs in the US overheated

Is the market for IPOs in the US overheated? Up until recently, I wouldn't have classified the recent demand for IPOs as anything like what we saw during the dot com bubble. However, things may just be starting to get out of hand as evidenced by last week's IPO for Castlight Health (CSLT). Castlight offers health information over the Web which can help consumers make informed medical choices and reduce insurance costs. Last year, the company had a whopping $13 million in revenue, despite retail giant Walmart being one its clients. Nevertheless investors bid the stock up from its initial price of $16 all the way to near $40. That gives this very unremarkable company an absurd valuation of over $3 billion! For those of you keeping track, that's 230x sales. Really? Does anyone remember Pets.com or Webvan? (VIEW LINK)