I'm a member, but in several months I think I (and my relatives) have manage to accumulate like $3.28 and $3 of that was a sign up bonus from Huggies. My grocery store and place where I get diapers, etc. don't have loyalty cards and you only get credit for products if they're identified on the loyalty card. (Just using your registered credit card doesn't work.) I get credit at the Mobil station and if I buy McDonalds gift certificates. That about it for me. Maybe I'm just not the right kind of shopper.
Oh well, maybe by the time my 1-year-old makes it to college she can buy a book or something. (Or maybe they'll change the program to make it a bit more user friendly to people like me . . .I buy several of the products, I just don't get any credit for them . . .)