Everybody (except perhaps sales people) know that some customers are just bad. They're difficult; they want special treatment; they expect a level of support far in excess of what they paid. They're like my father-in-law who wants Nordstrom support at a Wal-Mart price. Jim Anderson explores this situation in his article Tough Times Call For You To Fire Your Customers. He writes:
Wow! 150%!! Yeesh, that's some real difference. A PC maker told me that their profit margin only covers a few phone calls. My dentist "fires" bad customers periodically: those who frequently miss appointments without canceling and those don't pay their bills.
Can you afford bad customers! Read the article Tough Times Call For You To Fire Your Customers to help find and destroy bad customers.