When competition makes more than half of their revenue from ads, shutting off that revenue source by copying that UX and striking out pages of advertisements isn't very economically viable.
I have feature suggestions for hipmunk. I really hope you, or some other flights search site brings these two things:
1. Find cheapest flights between two countries (country->city, city->country, country->country). Some people don't mind traveling a little just to reach the airport from where they can find cheaper flights.
2. Bypass stopovers which levy transit visa. You can easily find my location so you can identify places where I will need to get transit visa even for stopovers and give me option to ignore flights with those stopovers.
> 1. Find cheapest flights between two countries (country->city, city->country, country->country). Some people don't mind traveling a little just to reach the airport from where they can find cheaper flights.
