Flying IAD-SFO non-rev on United. My brother had a ticket (He was on business). An earlier flight had cancelled, and this 777 that I thought was open was now packed. The gate agents were able to accomedate all the revenue passengers. With one seat left (First class on a 3 class 777), a revenue passenger from a later flight showed up. She demanded that she be placed on this flight, obviously to the dismay of the crew at the gate. She kept on demanding, despite the agents response that she could not be put in first because she paid for a coach ticket. The lady was really worked up.
I suddenly realized that I had not given my brother my car keys to drive home from SFO. I went up to the counter and politely asked the agent if I could get these keys to my brother. I told her my last name was Evans.
Agent 1: "Evans...Evans, he's a passenger, he's already on."
Agent 2: "No, this is Evans, he's number one on the standby list."
Agent 1: "Oh, thank god. I'm putting him on. I'm not giving that ***** a first class seat.
And so I went to my seat, put my stuff away, and we took off. Right after, I reclined my seat into the full lay flat bed, ate the meal, and slept the next 5 hours home. Best sleep I had gotten in a long time.
So be nice to the gate agents. They have the authority as to who gets on!