RIDDLE ME THIS!

Just went to Duane Reade--which I'm obsessed with--and I asked the young lady behind the counter if people actually got cash back. Because I don't like answering "no" before I can finish paying. That's just me--I never want cash back but that's only MY personal preference and you  may be different. She said that people got cash back so often that some people would actually buy 4 things in a row because you can only get $20 back per purchase. It was early and ma coffee was still kicking in so to be sure I was hearing correctly I asked her "So people actually make you ring up 4 separate items in order to get $80 cash when there is a bank across the street?" She said yes. I guess this is just how people do it now and this is just an old bitch ranting again. But does this strike anyone else as odd? It's definitely new. Maybe you can explain the upside to a fuzzy-headed senior.