I am DM and have complained about the same thing in the past. I typically get between 200,000-250,000 MQM a year on Delta (this year I split my miles with Continental, 178,000 MQM with Delta and 112,000 EQM with Continental) but I always buy my tickets last minute (Friday before a Monday departure or on my way to the airport for my return trip), this is due to the fact that I never know my schedule more than that in advance so I typically have YBM fares and I fly 45-50 weeks a year with maybe 6 or 7 international trips a year too. I have never counted how much I spend in a year but it has to be a lot, probably $3000-$4000 a month. The only flights I can get upgraded on are the outbound flights, sometimes I hold off and fly on Tue or Sun instead all depends on where I am traveling. For me it sucks knowing at the gate that someone with less miles than me and on a lower fare got upgraded but I didn't just because they baought their ticket two or three weeks earlier. I wish they held a few upgraded seats until departure for people like me