Shopping carts need good UX, too
User experience—it’s not just for websites and apps. It’s for anything that gets used. The experience of the person using the product is important.

Here’s a shopping cart I used at Ace Hardware. It has a cupholder, a modern convenience. How nice, right? But the cupholder on this shopping cart is at the bottom, close to the wheels. I would have to bend over and put my cafe latte down by my ankles. Not so convenient.
User experience is very often directly related to money. If a shopper on an e-commerce site has a hard time figuring out the purchase process, they may not make the purchase. So spending the time and money to ensure a good user experience is a wise investment for the e-retailer; there’s ROI.
How about this shopping cart? I don’t see the ROI on good usability with this product. Ace Hardware corporate must have bought a whole boatload of them for their stores. (Maybe these were cheaper than the ones with the cupholders up higher, within easy reach for the shopper. Who knows?) Am I going to stop shopping at Ace because their shopping carts are poorly designed? No. Does Ace have any incentive to buy better shopping carts, then? Not really. Is this still a poor user experience that gets me all worked up?
Yes. Yes it is.