In April, Google paid $700 million to buy the airfare software company ITA. On Tuesday, the tech giant put that acquisition to work, launching a flight search portal of its own called Google Travel. Google boasts that its new tool will offer "super-fast results," "a simple list of the most relevant flights," and a no-brainer way to discern which dates are the cheapest to fly. The new service is still fairly limited, but wary observers are asking what Google's foray into the travel business will mean for established sites like Kayak and Expedia: Is Google a threat?

Not yet: Using Kayak is simple, and all flight options are clearly presented, says Mark Hachman at PC Mag. Google's service, "by contrast, seems somewhat arbitrary," and, at times, confusing. To book a trip, you first select an outbound flight through Google. Then, return options appear in a "rather subtle dropdown window." After you select your flights, yet another dropdown window appears with a link to the airline website to purchase the flights. Not exactly seamless.
"Google's basic flight search tool quietly appears on web"

But one day, Google could rule travel: "Google is a giant in the search space, so it's not unreasonable to think that the company could capture serious market share in travel search," says Leena Rao at TechCrunch. Right now, Google Travel is a basic interface with limited options — you can't even book a one-way or multi-city flight. But if and when Google adds more features, Kayak and Expedia may start sweating.
"ITA-powered Google Travel launches; Kayak says its flight search is 'superior'"

And Bing may be nervous, too: It's not just Kayak and Expedia that need to worry, says Sean Ludwig at VentureBeat. Google Travel "could easily inflict damage on Bing Travel, one of the best features that Microsoft's No. 2 search engine has to offer." Right now, Bing is clearly superior, thanks to hotel search options and a "price predictor that tells you if you should buy flight tickets now or later." But as Google steps up its own offering, Microsoft will feel the heat.
"Google challenges Kayak, Bing Travel with new flight search tool"