In the olden days there used to ba an airline called Canadian Airlines. They used to code-share with AA many US-CAN routes. I was once flying LGA-YYZ on miles and ,y flight was cancelled. I had arrived late at the airport and they rebooked everyone on the next flight which left 1 hour later. I wasn't even in a rush, and therefore I dodn't consider this to be in any way an inconvenience, so I didn't make a peep about it. I still ended up with a "Y" fare trip that earned miles. (Although it was only a grand total of 500)