Actually, the best solution would be to make tickets non-refundable... for ANY reason. People wouldn't double book.. they'd show up when they were supposed to.. etc etc etc.... I was going from DFW to SLC years ago on a L-1011. (Big 3 engine airplane for all you young guys) It was overbooked by 65 people..... SIXTY FIVE... the gate agent told me.. don't worry.. you'll get on. I thought... the water here in Tejas is a little wierd.. but OK.. I never leave until the airplane pushes... and in the case of the L10, untill you see smoke coming out of all 3 engines... Guess what... I was in 1st class... the agent said that that flight was notorious for no shows... double booking.. etc... Now how much does THAT cost the airlines? But that's right.. those greedy airlines are not allowed to make a profit I guess...