Google is a threat to Priceline as well. They are both in hot water. To say that Expedia has a 5 year lead on Google is poor reasoning. Thats like saying the telegram has a lead on the telephone or horses had a lead on cars.
You cant compete with google. It would be like a little league baseball team vs the NY yankees.
Comparing Expedia Vs Priceline is also poor reasoning. It's like comparing ketchup vs mustard. Yes they are both great sauces but if you dont have the french fries they are both useless on their own.
Yahoo is pretty good, problem with gooogle it is too general, google hawaii and you will get a page of hits most unrealted to travel. Everyone knows that. Google is good when you are looking for something you do not know where else to find.