Overbooked flight-@Delta taking bids for volunteers...neat!

Checked in on-line at Delta for my flights to Chicago tomorrow...first flight is overbooked, and the check-in process hit me with a fascinating feature. Delta asked me to bid on what I'd take to give up my seat and take a different/later flight.

I'm guessing this saves them some time and potentially money. If they're willing to pay $400, and I bid $300, win for them, plus they can line up some potential volunteers before putting out the cattle call. That invariably ties up the gate agent with people who really aren't serious anyway, wasting everybody's time.