A customer is the most important person in this company-in person or by phone.  A customer is not dependent on us, we are dependent on him. 

A customer is not an interruption of our work, he is the purpose of it.  We are not doing a favour by serving him, he is doing us a favour by giving us the opportunity to do so.

A customer is not someone to argue or match wits with-nobody ever won an argument with a customer.  A customer is a person who brings us his wants-it is our job to handle them profitably to him and to ourselves.