Many stores still have credit card terminals printing the merchant copy with the whole credit card number on it. Let’s say you like a certain beer and buy it once or twice a week.
Scammers in this case are the cashiers, who are waiting for somebody who has a shopping habit of buying the same product regularly, while paying by credit card. Once or twice a month, the teller will just punch in your credit card number and charge your card for the specific product, taking the equivalent in cash out of the till. They will only do this for small amounts of money.
Next month, you look at your credit card statement but don’t see anything wrong, knowing that you go to that store on regular basis.
How to avoid: pay cash for these small amounts. The alternative is to always keep your till receipts and credit card receipts and check them together every month. If you’ve been scammed, this way you can ask to speak to the store’s manager about it with the proof of the conflicting receipts.