Get Rid of Bad Customers (Part II)
Dropping rude and unprofitable customers who are taking advantage of your business can increase both your revenue and employee contentment. However, you have to be careful. Customers don't like to be fired. They will be insulted and take the dismissal personally.
While people's feelings are always important, the value in remembering this is that a fired client will spread word of his or her bad experience, causing you to lose other existing or potential customers.
Don't dump too hastily. Discuss the disagreement first. Allow customers to question your expertise as long as you feel that you can still perform your job. After all, they are paying you.
If you do decide to get rid of a customer, do it in person, not over the phone or voicemail. You don't have to give customers all of the reasons that you are dropping them.
Pick a less harsh one, and avoid value judgments. Offer alternatives. Recommend someone else who might be better able to give them the service they want. If your ex-customer finds a better match because of you, he or she may forgive you and not spread word of his or her bad experience.

Comments
Your competitors need some business. Give them your bad customers by doing just what this note says. FIRE THEM. That way you have the profitable guys and he gets the DOGS
I started and ran a cooperative of free-lancers. We referred to each other (1st choice of the customers who saw our cards w our own phone #s). We had to get references from customers who used potential members, and all of us were really good. We got an excellent reputation, and lots more business to choose from.
The relevance is that (1) we warned each other about really bad customers, and (2) we referred to each other knowing who preferred and did well with what types of customers -- so they were much less likely to have a poor experience, and so were we.