With the ring of a bell, Kayak's co-founders silenced the relentless murmur of naysayers and cynics who said its IPO would never happen. The iconic sound opened NASDAQ trading on July 20, 2012, marking the debut of ticker symbol KYAK – a hard-won finale to a story that started nearly two years before. Investors have welcomed KYAK rather warmly thus far – after an initial pop, the first week of trading is up roughly 20% from the initial price of US$26. Whichever side of the fence you stood on for its IPO odds, there is much to admire about what Kayak's team has accomplished – it independently built a household name brand from scratch, hooked millions of users on a new website genre, and elbowed into a fiercely-competitive, mature industry that wasn't eager to make room for it. From its beginnings, Kayak has had controversy as a constant companion. Suppliers and online travel agencies (OTAs) have always been somewhat begrudging customers of metasearch referrals....