I have no idea who approved Denny's free Grand Slam Tuesday Morning promotion, however that person should be fired. Giving away free products as one shot deal is the worst kind of promotion. It uses valuable resources with zero, zero, let me repeat that zero payback. A one time promotion plus the Super Bowl ad will do nothing to change the habits of customers. If you are not changing customers habits than you have accomplished nothing. Yes they got lots of free press today. Lots of free press today is not a sustainable business model ever.
Promotions should compliment your offerings not appear haphazard like this promotion.