I just discovered the great online shopping sources some of the airline shopping portals have (yes, I know I'm slow on the uptake

).
I have a questions about Giftcertificates.com. The way I see it, I can go through a shopping portal and get 2 miles per dollar at gift certificates.com, use the gift certificate to get a hyatt gift check with a mileage earning credit card, and effectively triple dip - 3 airline miles per dollar, plus hotel points should I chose to use the gift checks for my own stay. This would also work with any other hotel chain.
Am I missing something?