Currently, Delta has a promotion that if you purchase $300 Delta gift card, you will receive a $20 Starbucks gift card.
Does this stack with the Amex's Delta gift card offer? Has anyone tried?
Not sure if that matter, but the link from Amex is delta.com/giftcards/amex, but the link from Delta is http://promo.giftcards.delta.com.

Edit: I went ahead and purchased the gift cards using the Delta link. Received Amex offer email a few hrs later. 👍