Got this flyer with my BA-Visa statement, however, I believe it will work also with Delta ...

"Earn double miles with Executive Club Dining - up to 20 miles dining dollar you spent between 12/01/01 and 2/28/02...
Call 1-800-869-2957 and mention code D790 ..."

They have an example on the flyer:

"Eat for $ 50 + and get 1,100 BA Miles"