5 grocery (one of which I guess I can throw away because the store went out of business).
CVS
Petsmart
Pet Supermarket.
I usually only use 1 grocery one and Petsmart. Pet Supermarket is worthless unless you buy bags of dry food from them (which I don't).
I don't find them annoying, I appreciate getting the stuff at the discounted price. And I keep them on their own little key ring so it doesn't interfer with my keys.
I just realized I have replied to this post, but never answered the question. I have 5, we don't have them for grocery stores and stuff around here. I have HBC (have to because I work for them), air miles, M&M's, Shoppers Drug Mart and one for the hair salon here (get 20% off because I work at the mall).
I've got three: Petco, The Body Shop, and one that is good at a number of German stores, including my favorite gourmet foods store.
We don't have Petco here, but I really stock up on dog and cat food, etc., when I visit my family every August, as my mom can no longer drive, so it's worthwhile having.
I've got Dominick's, CVS, Borders (and I hate Borders with a burning passion, so I don't even know why I have one) and Petsmart (and I never shop there, so that's also pointless.)
The Dominick's one is really handy and I use it every time I go in there. Which is often. CVS never seems to have anything on sale, so it never does me any good
Now that I think of it, I have a lot. I've got Jewel & Dominicks (grocery), Borders, Petsmart, and one for the Hallmark gift shop at work. I don't get discounts for that one, but they send me checks! I've gotten probably $60 worth over time from buying soda, etc.