Sorry to bump an old thread, but it looked like the most relevant (albeit tangential) one.
Originally Posted by
ITA Hacker
...we only consider a few hundred of the fastest flight options between the origins and destinations...
Have you considered a option that weighs the cost per mile rather than the most direct route and/or cheapest route? For mileage runners, that's a very important metric. For instance, earlier this year I was flying DFW-LAX on US. Rather than a semi-direct route, I was able to fly DFW-BOS-LAX for about 50% more and earn about 3 times as many miles. ITA didn't find that option for me. I had to use "dfw::us+ bos us+" and "lax::us+ bos us+". I only knew to look for BOS because there were dirt cheap prices DFW-BOS and BOS-LAX (which I found with FareCompare's FlyerTalk page).
Another nice feature would be the ability to sort the list of flights by the cost per mile.