Is your wallet stuffed with discount club cards?
They are as common at the check out line as grocery carts and scanners.
If you want a discount you need to show your club or loyalty card, and these days those cards are adding up.
Many of us carry them around wherever we go, in our wallets, our purses or key chains.
It's a regular pat on the back, telling us how special we are for joining the club and offering a Member's Only discount.
It's not just grocery stores pushing them, it's drug stores, even pet stores.
Why do they have the loyalty cards?
"They're studying consumer buying patterns, they're studying regional preferences," explains San Diego State University marketing professor George Belch.
Using every purchase as a personal survey of your buying habits, information that can be used for future marketing or discounts.
Not every store chain uses them.
Low cost giants like Target and Walmart don't have club cards and many smaller stores can't afford them.
Still the loyalty cards don't seem to be going anywhere, and that means more cards to carry, more to keep track of.
So if you want to use the club card but you don't want to carry them around, and you don't want to give your phone number to the clerk, there's an option: Using your smart phone.
Cardstar is one of a few phone application that lets you combine all your club cards onto the screen of your smart phone.
Instead of carrying around each individual card, you simply take a picture of the bar code on the back of your card, link it to the particular grocery or drug store and it stores the code.
No need to hand over your card or give your phone number, the clerk just scans the barcode on the screen of your phone.