I do get upgrades a lot of the time but I am pretty sure its cause I book in upgradeable fare classes (y,b,m) and then use my old system wide upgrades (last years platinum and diamond benefit choice) the 13% is when business Z is cheaper then going with M, and 12% when my dates are not flexible and I have to go and don't buy full J. Hope that shines a little light on it, I was more upset that they quoted that part like I was getting a great deal where as I feel that I am paying for that great deal.