Valid through ?
Hyatt is currently offering 10% off Hyatt gift cards for Gold Passport members. Since it is free to join their program, that makes this deal available to everyone.
To get the discount, go to certificates.hyatt.com and enter promo code GPGIFT14 during checkout.
Currently, only by-mail certificates are available at a discount, but e-gift cards with free shipping are expected to become available mid November.
Please see certificates.hyatt.com for details and terms associated with gift cards and gift certificates.
Increased savings with Amex business cards (OPEN Savings)
I don’t yet have confirmation of this for the current promotion, but in the past, purchases of Hyatt gift cards have been eligible for Amex OPEN automatic statement credits. Amex offers small-business cardholders automatic rebates with certain vendors and that includes Hyatt. That means that you can save an additional 5% by paying with an Amex small business card. Details here.
Increased savings with Amex Simply Cash
If you have the Amex Simply Cash card and chose hotels as your 3% category, you can earn both the 5% OPEN Savings and 3% cash back from this card. NOTE: see warning about this in the comments.