What's interesting is that as the compensation for VDB goes up, not only does it increase the likelihood of getting a volunteer, but it also increases the pool of volunteers who would accept contingent on the accommodations provided by the carrier. Does the airline then attempt to determine what all said accommodations are in order to determine which pax is the least costly to VDB?
I can see a new area for travel blogging: how much free swag one can get negotiating a VDB. It would be pretty funny to watch, akin to those crazy bazaars where haggling is the norm. Not sure how time efficient it would be though, especially if has to be done in the plane because pax are already seated.