I had this on AS a while back. SEA-SFO went mechanical, so they put everybody on my SEA-OAK flight and we went SEA-SFO-OAK.
That second segment was a lot of fun. The pilots goofed around with the announcement..."Welcome aboard our new non-stop service from San Francisco to Oakland. Our flying time today will be six minutes, with a cruising altitude of 3,000 feet. The weather in Oakland is pretty much what you see out your window."
No 'compensation' per se, but drinks were on the house from SEA-SFO for all pax.