I really enjoyed learning about how Kroger keeps me a Kroger shopper, while I pursue my best economic interest by screwing over Walgreen's (I only shop there for prescriptions and deeply discounted coupon items available to anyone). It's a wonderful read for anyone in a business that makes money by selling to the same person more than once!! Highly recommended.
I gave it 4/5 because it is a bit dated -- one of the main examples is Ukrop's, which is now out of business. Also, I don't think the measurements are as useful to someone not in the retail business. Finally, there's a huge emphasis on "frequent card user" programs -- which is unlikely to catch on with someone who shops with you less than once a week. Or is it??? That's the question :) :) :) :)