The principle I think you're hinting at here is one of reinforcing good behaviour and extinguishing bad behaviour, à la Skinner. However, this can only be done

The principle I think you're hinting at here is one of reinforcing good behaviour and extinguishing bad behaviour, à la Skinner. However, this can only be done over time, with repeated interactions. The mechanism described in the article doesn't seek to alter the behaviour of the customers, each of whom may never be seen again. Rather, it is a defence mechanism for the employee.