On Sunday I was one of four or five volunteers who got $800 each for taking a JFK-RDU flight that left just four hours later. Not bad.
While I was waiting for my new flight to depart there was a call for volunteers on a JFK-Nashville plane to give up their seats to get rebooked for a flight the next morning. I think the offer started at $800 but less than one minute later the announcer offered $1300. A few minutes later the offer got raised to $1800, then $1900 (and every offer included overnight hotel). I saw some happy faces over at that gate.