Do you realize that Delta also has a spend requirement for status (MQD's)? For Platinum it is 9000 MQD's. It can be waived if you spend $25000/year on a DL Amex card, but otherwise, you really need to understand the MQD earnings on flights before going off and booking a bunch of mileage runs. For Delta flights, it is basically be what you spend on the flights minus taxes and fees. For partners, you can often do better by booking premium cabins.