Here is the info as posted by Northwest:
Get up to 35,000 bonus miles.
You’ll receive 25,000 bonus miles after your very first purchase1 and another 10,000 bonus miles after you make $1,000 in purchases within your first three months of becoming a Cardmember2. That’s more than enough for an Award Ticket3!
Add to the Miles You Already Have
Later this year, WorldPerks will merge into the SkyMiles® program4. Right now, you can link your WorldPerks and SkyMiles accounts and transfer miles between them. And the Gold Delta SkyMiles Credit Card is the only Credit Card that lets you add to the miles you already have.
Keep the Miles Coming, and So Much More
In addition to earning miles, you pay no annual fee the first year – a $95 savings5. You also get double miles on Delta and Northwest purchases6, on top of earning one mile on nearly every dollar spent elsewhere7. And you enjoy the exclusive Pay with Miles feature, which lets you use miles to pay for a portion or all of Delta and Northwest fares8.
This Offer Won’t Last Long
Get up to 35,000 bonus miles. Hurry, this offer ends May 31, 2009. This exclusive offer is only available online. Apply for Gold Delta SkyMiles Credit Card now.
As always be sure you carefully read all the terms and conditions.