Amazon on Monday unveiled its vision for the future of grocery stores, and retail stores in general: a smart store that knows when you've selected an item, and automatically charges you for your selected items upon leaving the store. There are no cashiers, no registers, and no checkout lines.

Image: Amazon

This concept, called "Amazon Go," is extremely clever — and one of the reasons it sounds so appealing is because it eliminates the worst aspect of the grocery store experience: waiting in line to buy your items.

Think about any grocery store visit you've had: It can be fun to look at all the food, navigate and browse the aisles, pick various foods and throw them into your cart. It's an adventure! But the food-shopping experience almost always turns sour when you get to the checkout part. Even when there are no lines, the checkout process is slow — you have to look at all the items you selected again as they get scanned — and then you have to pay for everything, sign a receipt, and wait for all of your food to be placed into bags.

It takes time, a lot of waiting, and it's generally boring.

That's why Amazon Go is a sound concept. There, the whole shopping experience happens on your phone — specifically, you download the Amazon Go app before visiting the store, scan a QR code to get in, and the store recognizes which items you've selected and charges your Amazon account once you've left the store. In this sense, it's kind of like Uber, since initial entry requires using a phone app, and it automatically charges your card once the experience is over — no need to swipe a card and wait for a receipt.