If you're a customer of Boston Market you will like this deal: if you buy a $25 gift card they'll give you a $5 bonus card. That's a 20% discount the way I see it if you are going to use it. This came by email and it says quantities are limited. Not bad for a stocking stuffer or to give yourself an extra $5. Not available online.
Edited to add a gift card promotion from the Daily Grill: If you buy a $50 gift card, there is a $10 bonus promotional card that can be redeemed in January and February 2012. This deal is available on their website.
Cheesecake Factory is offering $25 gift cards -- their bonus is a slice of cheesecake. About the same value as the others.
Any more of these? Is 20% the typical promotional bonus value this year?