I have a situation that I cannot figure out and would like everyone's help with.

I took the 11:30pm red-eye from SEA->DTW last Friday. For some reason that eludes me, I received a 50% MQM mileage bonus on that flight.

Is there some rule about red-eyes that I don't know about? Do they come with bonus miles for the suffering?

For those that are curious, this was a M fare. Also, according to my promotions page, the only item I'm currently enrolled in is the FO mileage bonus promotion that's making the rounds. (That promotion is not supposed to start until April 1.)

Does anyone know where these miles came from? Not that I'm complaining