Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Is it bad etiquette to use a credit or debit card to pay for single figure amounts at the POS
Etiquette or not, it is hurting the seller. The transaction fees have usually minimums, so if the actual transaction is below the minimum - they'll pay larger fee on the transaction (relatively). As an example, assume minimum fee for a debit card swipe is 20 cents, or 2% of the transaction. For a transaction of $10 and above, the fee will be 2% of the transaction. But for $1.67, the fee becomes 12% of the transaction. 6 times more expensive for the seller. Basically, the sale was most likely at a loss for them (they usually have very low margins, especially for a "dollar" store). So take that into account as well.