[Update 10/5/2012] The original link has stopped working, but here is the new link. Please follow the same steps outlined in the original post.
https://www265.americanexpress.com/apisites/microsite-framedapp/apply/delta-gold-skymiles-credit-card/U7-1000-46?offer&affilSiteId=Deltanotlgn&affilCtgyCd=COB&pmcVendorCode=U7&additionalOffer=false
&firstName=John&lastName=Smith&membershipNumber=0123456789
[Original Post 9/16/2012] This new Amex Gold Delta offer gives you 70,000 miles (25,000 miles after the 1st purchase and an additional 45,000 miles after you spend $5,000 within 6 months) and $100 credit (if you buy a Delta ticket within 3 months). This offer is targeted; however it seems that there is a workaround to "customize" the offer to yourself. Here is what you need to do:
1. Copy and paste this link to your browser without hitting enter:
https://www262.americanexpress.com/apisites/microsite-framedapp/apply/delta-gold-skymiles-credit-card/U7-1000-46?offer&affilSiteId=Deltanotlgn&affilCtgyCd=COB&pmcVendorCode=U7&additionalOffer=false
&firstName=John&lastName=Smith&membershipNumber=0123456789
2. Change "John" to your first name, "Smith" to your last name, "0123456789" to your Delta account number, and then hit enter.
3. The form is a little weird. When you click "First Name" it will say "Middle Initial" and you need to provide the later. When you click "Last Name" it will say "Name on Card" and you need to provide the later. After you finish all your information, go to the next step you will see your first name and last name have been correctly displayed.
We are not sure if this will work out for everyone so try at your own risk!