I disagree. I think you underestimate how insidious the google model is and underestimate how much power they yield.
Exepdia has to pay google to be on top of a search for travel sites. Otherwise the search results are so called organic. Unfortunately, this is a euphanism because Google will divert traffic despite what they say to what profits them the most.
In addition Google chrome is fast becoming the most popular browser as well.
Effectively thats 2 huge obstacles that google can place in front of Expedia or Priceline or anyone else they want if it drives traffic away from there service.