Dear Bad Customers,
Recruiting and training a new staff member costs us $X in salary and recruitment costs, and $Y in opportunity costs - that being things the management and senior staff could be doing instead of recruiting and training.
If you wish to drive our staff away, please be advised that we require an absolute minimum of $(X+Y) in profit for each staff member who quits because of you.
Being rude to our staff, arguing with them about things they have no control over, criticising them directly or in their hearing, or insulting them will be considered an attempt to drive our staff away. As will anything other than being a polite, reasonable human being.
If you have a problem with a staff member, request to speak to a manager. It is our job to train and discipline our staff, and we wish to have the opportunity to do it well. That is an opportunity you deprive us of when you try to do it yourself - and since you are usually unaware of the full circumstances, you do it badly. This also costs us money.
So to repeat: if you drive our staff away, we require an absolute minimum of $(X+Y) in profit for each staff member who quits because of you. If you merely participate (along with others like you) in driving our staff away, we will prorate these costs based on the percentage of responsibility you have in our incurring these costs.
You may be unfamiliar with accounting terms, so I will clarify: profit is the difference between what an item or service costs us to provide, and what you pay. It is insufficient for you to spend $(X+Y) in our store, you must spend $(X+Y), plus staffing costs, plus a share of utilities, services, depreciation and rent, plus a share of taxes and administrative costs, plus the wholesale price and distribution costs of any goods you purchase or which we expend on your behalf. We would be happy to provide an estimate of the total amount you must expend, but we will also require you to pay the cost of that service.
Be advised that if you only provide $(X+Y) profit, we will still fire you because of the sheer frustration you cause, the fact that we would not then gain anything from serving you, and the fact that it is better for us to spend our time and effort on customers who are pleasant and who we actually do obtain value from.
We leave it to you to decide how much extra you will need to spend in our store to make it worth our while serving you.
The management and senior staff of This Store.