I was flying on May 29 LAX-HNL. At the gate they had a Hawaii background for selfies, and a "spin the wheel" for a prize set up. Just prior to boarding my name was paged and after freaking out that I lost my seat or was downgraded, the gate agent invited me to spin the wheel for a prize. I won a $100 travel certificate. Today I received an email from United Customer Care, with a $200 travel certificate. Typical United: the email started with, "We apologize for the inconvenience you experienced on your recent trip with United."
I'm not complaining, but I won the $100 certificate and they gave me a $200 certificate. I don't know if I got more because I am a 1K or the gate agent was being nice. Nevertheless it was a nice unexpected surprise. I do not think they called any other passengers for the spin.