Back a number of years ago, I was booked on USAir from San Diego to Pittsburg.

After boarding, the agent came on board and asked for two volunteers to deplane and board a later flight in exchange for a free round trip voucher. I kind of gave a half hearted raise of the hand and asked when I would arrive on the later flight. When told, I explained that I would arrive too late for a dinner meeting so I chose to stay on the flight.

After finding only one other person to leave the flight, the agent returned to me and offered 2 free round trip vouchers. I decided to accept, left the aircraft with the agent and was brought to the next gate where a manager was completing the voucher for the lady who had left the flight on the first call. The lady overhearing that I was recieving 2 vouchers asked if she would also recieve 2. The manager's answer was, "Sorry lady, you got off the airplane for one."