I imagine some were shaking in their boots at online travel booking sites today when Google announced their $700 million acquisition of ITA Software. As previously mentioned the search giant has been working on a deal with the travel search engine for some time now.
Airfare search is a huge business. If Google becomes the defacto airfare search engine, as it is now for web searches, it will play a game changing role in the online airline ticketing business. Even if Google continues to redirect search result traffic to a booking partner for ticketing, I am sure it will come at a price. Namely increased referrer fees in form of Adsense or other paid partnerships by the big sites.
The big losers in this announcement are sites like Kayak, Sidestep and Cheapair which may lose their edge when Google throws its computing might behind the airfare search problem. Their click referral business could certainly be impacted once people start clicking on Google instead.