HTML emails make perfect sense when it comes to restaurants. Consumers have lots of choices, and most always have a list of favorites. Restaurants with good mailing lists that send out valuable coupons and offers can increase their chances of being the choice of the night. Deal driven consumers are much more likely to make a selection based on this when the emails consistently contain solid deals. Blasting users with useless information will only trigger their mental filter. Seems the point is to not forgot the purpose. Consumers don't care about the politics of management and some food chain, they do care about getting a better deal though! The series of coupons from Dominos here and here seem to be a prime example of this focused communication.