When I do 10 searches, each of those searches hits a substantial subset of every flight that could satisfy my travel need. Suppose I want to fly BOS to LAS for re:invent. For the outbound leg, I’m probably searching for Sat through Tues, every carrier, every leg, every cabin. That means a leg BOS-SLC, BOS-ORD, BOS-ATL, BOS-LAX, etc are all considered.
You can’t easily prune the tree on cost or time because you don’t know my preferences. You might notice that most pruning is done only on segment count, with (almost?)no one by default showing itineraries with 2 additional segments over shortest. I might prefer a carrier (I do), but even if I do, I still want to see the other choices, because my preference isn’t thousands of dollars strong.
Rather than 10 queries per seat sold, I’d not be surprised if the actual query count was 10K or more.
You can’t easily prune the tree on cost or time because you don’t know my preferences. You might notice that most pruning is done only on segment count, with (almost?)no one by default showing itineraries with 2 additional segments over shortest. I might prefer a carrier (I do), but even if I do, I still want to see the other choices, because my preference isn’t thousands of dollars strong.
Rather than 10 queries per seat sold, I’d not be surprised if the actual query count was 10K or more.