It allows them to confirm what you bought is the same as what you scanned. It also makes sure you didn’t miss-count your multiple items. (Either double-scanning an item or failing to scan an item.)
Having now lived in lower-class areas and gentrified areas, stores that can afford a self-checkout kiosk tend to trust poor people less. (At the same time, they over-estimate their losses from theft or accidental shrinkage).
I believe they were introduced as an inventory control mechanism, though they got way worse as customer-supplied bags became the norm.
But they already know what is sold by the scanned barcodes. What do the scales add to that?
It allows them to confirm what you bought is the same as what you scanned. It also makes sure you didn’t miss-count your multiple items. (Either double-scanning an item or failing to scan an item.)
Having now lived in lower-class areas and gentrified areas, stores that can afford a self-checkout kiosk tend to trust poor people less. (At the same time, they over-estimate their losses from theft or accidental shrinkage).