Employees usually are much faster than customers to scan groceries - thousands hours of practice make perfect. Plus, those anti-theft machines that give you ins

Employees usually are much faster than customers to scan groceries - thousands hours of practice make perfect. Plus, those anti-theft machines that give you instructions "scan next item, put item in the bag, take the last item out of the bag" - they slow things down considerably. Also, the number of labor required stays the same, just now it's unpaid labor.