Originally Posted by DL-Don

MQM boosts went into effect with the introduction of the DL branded AMEX cards.

In the early days of the original Delta Frequent Flyer Program, AMEX spend on Delta counted toward MM status. Sadly, my employer gave me a Diner's Club card for travel. The DC card spend DID NOT count toward MM status. Also in those days, minimum mileage credit was 1000 miles per segment. I DID benefit from that! ^