Best Consumer Sales Invention of the 20th Century

Using a barcode scanner was something that I remember having to get used to when they first started using them back in the 80's in the convenience store I worked at. Now they're everywhere and for good reason. They make merchandise control, price control, and check out control much more accurate. A good barcode scanner saves money for both the merchant and the customer. If merchants don't loose money on check out inaccuracies, merchandise loss, or inventory control they can keep their prices lower and that benefits them both. The barcode scanner is the best invention for consumer sales in the 20th century.