Last week's column about loading e-coupons to loyalty cards led to reader comments on store loyalty cards! Love them or loathe them, my readers are chiming in. Several were concerned about privacy.

Q: I have a shopper's card that you can load e-coupons to. I wonder what information the store tracks. I'm sure there's a list somewhere of items I often purchase since my store gives me e-coupons for things I have bought before. Should I worry about privacy?

Q: My husband hates using a store card to get a better price. He says the store is keeping track of what we buy. But I think it's silly to pay more to prevent a retailer from keeping a list of what I'm buying. Who's right?

A: If you use a loyalty card at the supermarket or drugstore, there will be a list of what you've bought. Stores call this “data mining” and use the information as ongoing data about what shoppers buy most frequently, and to help plan promotional offers.

If your store has a Catalina coupon printer, you may have noticed the coupons that print at checkout are often based on your past purchases. This data is often tied to your store's loyalty card. But not always. While I understand many people are concerned about privacy, and some may find the idea of data mining unsettling, stores still can track your purchase history even if you don't use a loyalty card. Many, including Walgreens and Target, tie purchase history to the credit card you use to pay, not your loyalty card.

In fact, Target's data management is so thorough, its predictive analytics department can identify what kind of shopper you are and what might be going on in your life by looking at your purchase patterns. The New York Times ran an article about Target's ability to determine if a customer is pregnant by watching for a specific sequence of purchased items. And it isn't just diapers or formula. The list includes lotion, washcloths and cotton balls. The data was so sound that Target could even tell what trimester the shopper was in based on what she bought, all without a loyalty card.

So where does this leave us? If you don't want your purchases tracked, you should forgo using a loyalty card and pay cash for every item, at every store. But for shoppers who are loyal to their loyalty cards, consider the upside: Because the store knows what you're buying, you might receive promotional offers and coupons you might not know about otherwise.

Jill Cataldo, a coupon workshop instructor, writer and mother of three, never passes up a good deal. Learn more about couponing at her website, www.jillcataldo.com.