At Marriott, when you buy a gift card of $50 or more, the card automatically receives an extra 10% bonus when you apply coupon code "MMF" at checkout. (Click on "Shop Marriott" to find them.) That's the first extra bonus coupon we've seen from Marriott. Of note, you will see a message at checkout that the extra value has been added but the amount will not show in your cart; only the actual amount charged to your card will be shown. Coupon ends December 31.