Originally Posted by
gadgetfreaky
don't they make more money if they sell miles for it tho?
Yes, but airlines play the long game. For a given flight, the airline should cut the price of seats down to a minimal amount, reflecting cost of fuel, meal, and ground/air servicing for the added passenger as it gets close to flight time, because better to sell the seat for $50 (or 5000 miles) than have it go empty. But they don't, because to do so would lead potential flyers to hold out on buying tickets until the price decreases, and the airline wouldn't be able extract the maximum revenue from that one flyer who really, really needs to fly to AMS today and will pay $9000 to do it.