Free - 10% of Nothing!

Okay, I admit that I have already written about some of my frustrations with loyalty programs that center around getting a store credit card for 10% off one's purchase for one day. It has always seemed to me, that in order to offset the huge hassle of having another credit card to manage every month, that you need to be buying at least $900 of merchandise to get a $90 discount.
However, on the opposite end of the spectrum, over the week-end, I got offered 10% off nothing! I had bought something in the store for about $50 and in the process of taking it back, found something else I liked for exactly the same price. Consequently, I decided just to do a direct swap - return the item I didn't want and buy the one I did. In the process of doing the transaction, the sales associate asked me if I wanted to save 10% by taking out a store credit card. I asked her whether it was possible to save 10% on nothing since I didn't owe anything. She looked at me like I was barking mad and asked me what I was talking about. The more I tried to explain, the more convoluted our conversation became until I finally just had to stop trying to clarify the issue and tell her that I would regretfully pass on the credit card offer.
Oh well - at least it provided me with a chuckle........