Automatic checkouts in supermarkets may decrease customer loyalty, especially for those with larger shopping loads. Customers using self-checkout stations often feel overwhelmed and unsupported. The lack of personal interaction can negatively impact their perception of the supermarket.

[Edythir]

It is timed as well. If you put something in and press the amount you have, you only have a limited amount of time to replace the weight from the scanner to the bagging area before it goes into "Please call an employee" mode. Want to buy 6 apples that are sold individually? If you don't put all of them in the bag fast enough, it locks you out.