Amex is currently running an offer for $25 off $200 at NewEgg.com. How does those of us that like to travel? Well, it’s a little known fact that NewEgg sells many third part gift cards (including AA and Hyatt)!
Make sure to log in and add the (widely targeted) offer to your Amex card first. You can also sign up via twitter by linking your Amex card and tweeting #amexnewegg.
The T&C’s don’t specifically exclude gift cards and users on slickdeals say that they’ve been able to do this in the past so I’m relatively comfortable with saying you won’t have a problem getting the offer to apply.
Edit: Looks like they’re currently out of the $250 AA cards but the $250 Hyatt cards are still available! Make sure to keep your eye out.