The offer is at skymall.com/25000 and runs through 11:59pm tonight (Mountain time) only. They’ll award 25,000 Delta miles for making $500 in net purchases (excluding tax and shipping) today only.
It’s not valid on gift cards, and some items and vendors are ineligible and per the terms and conditions of the offer that’ll be “noted on the product page.”
Discussion on Flyertalk is here.
Now, I don’t have time to find anything on the Skymall site that I want, and I don’t want to do this just for the miles (as I won’t spend 2 cents a mile for Skypesos). But if you have any interest in the actual stuff you’d purchase, then this is a pretty rockin’ offer.