Want to lose me as a customer, follow these guides. If you instead want me to continue shopping with you, you should ignore these guides.
Have a "store policy" of limiting creditcard transactions to amounts over $10.
Where do you make the most profit in retail? Low ticket items. You should make it harder for me to purchase these high profit items by making me leave your store and go to the ATM and pay $2 to withdraw cash because it is not my bank's ATM. Of course moments after I leave your store I will decide I don't actually need the melon-baller I was trying to buy from you. Well done.
The finest example of this is when I tried to buy two coffees from Gloria Jeans for six dollars. The assistant informed me that I needed to spend $10 to use my creditcard. I shrugged and pointed at a cake. After she put the cake on a plate she rang up the order on the register and it came to $9.95.
She looked at me… waiting.
I said "Don't be stupid!"
When she asked her manager what she should do, the manager said "Do it, but just this once."
Well done manager-lady. This was the last coffee I ever ordered at Gloria Jeans.