Bet on an IPO ?

Today's Alibaba IPO showed that good money can be made from buying into an IPO. I think it's nothing more than gambling. When a company goes public, there is only a limited amount of information available about its finances, historical records etc. So it's hard to establish if this is a good long term investment. I've invested in IPO's in the past -- Red Hat and Cobalt Systems. With one I quickly made some money, with the other my investment was a tax write-off. So I'm done with IPOs, and would rather patiently, actively search for good investments that throw off money for some time to come.