"Julia Altshuler" > wrote in message
news:ffEKc.126594$Oq2.35625@attbi_s52...
> The most benign explanation is that it allows the store to gather
> marketing information.
>
>
> For example, the store knows that more people will buy a particular
> brand of orange juice if they put it on sale from a regular price of
> $2.99/half gallon down to $2.19/half gallon, but they also have good
> reason to want to know details.
>
>
> Do the people who buy it on sale stock up and then not buy it the
> following week? Do the people who buy it on sale normally buy a less
> expensive brand and switch when the more expensive stuff goes on sale?
> Do the people who never buy orange juice try it when the price goes down?
>
>
> The store can gather all sorts of useful information if they can track a
> particular customer's buying habits. They can discover if the person
> who avoids orange juice with sugar added also avoids all products with
> added sugar or just orange juice. Does that customer ever buy candy, or
> does the customer also buy diet soda? It tells how well advertising is
> working in specific ways. Do customers who buy premium ice cream read
> the ads in the local paper, or do they respond to a promotion at the
> local school?
>
>
> The information is incredibly useful in setting prices. This way they
> can discover just how much the customer will pay for orange juice before
> switching to apple or grape or no juice at all. It helps them discover
> how high the prices can go before the customer will buy groceries
elsewhere.

They could gather all this information by issuing cards without collecting
your name and address.