Regarding cutbacks caused by rule breakers, I assume that part of the reason that United has switched from paper upgrades to electronic upgrades in all but one case (SWUs), is because people were selling them in contravention of the Mileage Plus rules. So now, instead of just being able to gift a North American upgrade to a friend of mine, I have to walk 10 blocks to the city ticket office, wait in line, and show identification proving that I'm me so that I can have the electronic upgrade attached to that other person's ticket. It is a huge pain in the .... And aside from cost savings the airline realized from switching from paper to electronic certs, I presume a large part of the reason for this change is because people were routinely selling these certs even though the rules specifically prohibit that. But I don't work for the airline so I can't say for certain that that's the reason for the change.