Did you ever fire a bad customer? I don't think it happens often enough.
Whether you own a retail business with many customers and small transactions, or a services or commercial business with fewer customers and larger transactions, forget the 80:20 rule. It's pretty easy to identify the 5% of our customers who cause 95% of our grief.
Even when we know that a particular customer is more difficult than they are worth, many of us can't bring ourselves to politely suggest that their needs may be better met elsewhere. What about the lost sale? What if they drive away other customers through bad references?
In reality we are better off focusing our energy on those customers who value what we offer and treat us with respect. We know this to be the case in other aspects of society. We are less tolerant today of bullying and abuse in our personal lives. It's time we rejected this behavior in our business transactions.
Browbeating should never be tolerated when making a sale. When faced with it, don't engage, walk away instead. If this behavior is what you must typically endure to close deals, then you should find a new way to make a living.
If this sounds a bit ivory tower-ish, just remind yourself that every time you accede to being abused, you reinforce the legitimacy of that behavior to the abuser. Every time you refuse to be abused, you send a powerful negative message to the abuser.
Rejecting bullying and abuse are as important to improving business transactions as they are to other human interactions.
Nobody is always on the their best behavior in today's stress-filled world, so we need some tolerance for bad moods on occasion. All of us who deal with customers soon develop the communication skills to distinguish between a bad mood and an abusive style.
Be fair, pleasant, and principled in your dealings with customers. Accept nothing less from them. The few customers you fire will be replaced by others you will be glad you made room for.