As part of my campaign travels I regularly fly on Delta Airlines, and have achieved “Medallion” status in the past. A few years ago they implemented “roll over miles” which would allow you to roll over the excess miles (over a given Medallion level) towards the next year’s status. Today they rolled out a new policy called “Medallion Qualification Dollars” (MQDs) that require you to not only meet a mileage threshold but a dollar expenditure threshold to achieve elite status. Of course the MQDs cannot be rolled over, and are calculated such that they are effectively eliminating the effect of roll over miles while simultaneously eliminating frequent fliers who travel on the lowest fares. Talk about killing two birds with one stone! While this probably means yours truly will spend even more time sitting in coach, from an economic perspective it makes sense to just move the whole program onto a dollar spent basis. However that will probably not sit well with the masses who make a hobby out of frequent flier mileage arbitrage.