Originally Posted by
TripleD
That is actually a useful price point. Platinum for you = $9000. I looked and it appears I reach Diamond at about $12,000-$15,000 (which I often exceed). The cost for Delta is the loss of fees for use of the FF lounge from Amex Platinum and upgrades they might be able to sell (but I say might, as they usually cannot).
You also have to remember one more important thing... a DM or a PM often controls the itinerary for a larger group, be it an entire family or business associates etc.
So if you chase the PM or DM away, that person will take his family to the competition as well.