That's the point that the OP is making - paying the difference to Y->J (repricing the ticket), as in your MMB example, is cheaper than upgrade for cash offers that you get later on, which we all know to be stupidly expensive. It's easy to look at this and think "that doesn't make sense", but QR has the data, and if they are choosing to market it this way it probably makes commercial sense. Maybe some flyers are impulsive, or only want to upgrade one leg...who knows?