Let me get this straight. Someone who paid $10k for a ticket takes a voluntary bump down to Y for a voucher? If there is such a person, I know of a bridge in New York that may be for sale. That person needs to have their brains examined. More realistically, I think that when the airlines overbook, they know that there is always going to be a number of individuals who upgraded their inexpensive coach ticket and who would gladly go back to coach for a reasonable sum of $$$ and the return of their upgrade sticker/voucher/coupon for use on a later flight. Also, if on the chance that the entire cabin paid full price $10,000 for their ticket, there is always going to be someone with a flexible schedule who will gladly take a different flight (staying in the same or better class of service so as to receive the same "value" of ticket) in exchange for $$$. Look at all of us here on FT.