I don't think you can do that. AFAIK the gift cards can't be used on line, so you can purchase them at a discount, but not get miles for using them. On the other hand, if you use a mile producing credit card to make the gift card purchase, you should get miles for the purchase of the gift card. Or, right now it ought to qualify for the current quarter 5% promo (up to $400) from Discover Card, but I can't say I've done that. (Or, it would qualify for the 5% Citi Cashreturns card introductory promo if you are within the 3 month window). So, potentially you could get 1000 miles from your credit card, plus $30 from ebates for a $1000 purchase, or $20 cashback from discover, plus $12 from Ebates for a $400 purchase.

Alternatively, right now you can register for the Moms, Dads and Grads NWA worldperks promo, then go through the NWA portal to purchase Home Depot gift cards. That gets you miles or $ from the credit card you use, 1 Worldperks mile per $ spent and 500 miles per $50 of giftcertificates (up to 50,000 miles). Your $1000 purchase could net 1000 miles from your credit card, 1000 miles from the mall and 10,000 bonus miles. That could be the better deal if you have a use for Worldperks miles.