DL should really just simplify things... "Come fly a round trip with us anytime and we'll grant you immediate silver status, fly a second and earn gold, and for only one more enjoy all the benefits of platinum. And, for each trip paid for with your AMEX card you get an automatic bump to the next status level immediately when booking. Of course, as always, endure a delay or cancellation due to our sloppy computer systems or any other reason and receive automatic Diamond status."