The past two years Denny’s restaurants have offered an interesting promotion the Tuesday after the Super Bowl – a Free ‘Grand Slam’ breakfast. It created a great deal of buzz in 2009 and again this year and reportedly cost less than $ 1.50 each when you factor in that many people still had to pay for coffee ($ 1.85) and/or juice ($ 1.99).

What continues to be a mystery is how this promotion created new customers (I assume that it did) and how loyal have those new customers become? My marketing intuition suggests the tactic should have been successful but without an attribution model it’s a gray area to everyone except those at Denny’s and Denny’s marketing agencies (or so I hope).

More recently Denny’s has teamed up with AARP and reports are that the discount program http://bit.ly/eSeIh1 has drawn more than 2 million members. AARP members who show their membership cards at Denny’s restaurants on any day of the week between 4 and 10 p.m. get 20% off the total check amount. The card also allows members and their guests to purchase a cup of coffee for $1 per person on any day, 24 hours a day.

Again I really like the idea and imagine that it will have a high probability of success. But how is it being measured? I expect that Denny’s would be measuring the lifetime value (LTV) of the new customers these promotions have brought into the funnel. The promotion is seemingly also a smart one for AARP as it delivers added value to its members (of which I am one but I was totally unaware of this promotion – hmmm).

Since Denny’s continues to do out-of-the ordinary promotions it’s easy to surmise that they must be working to some degree. After all like the person who goes to the doctor and says ‘Doctor it hurts when I do this’ and the doctors says ‘Stop doing that’, Denny’s has to know the promotions have worked to some degree or why continue them, right?

How about Denny’s sharing the numbers so the rest of us can see how truly effective these campaigns have been over a broader scale? I’d like to think that the marketing community would be eager to have Denny’s share what would be very valuable information.