Qual a margem de cada cliente?

Empresa carregada de dívidas, incapaz de suportar os seus custos fecha. Televisões interrogam trabalhadores à entrada da empresa:
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- É uma surpresa para nós! Estávamos cheios de encomendas! Tem de haver falcatrua do empresário.
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"We also came across some customers we didn’t want. They were mainly small customers who had already heard from our collectors— repeatedly. We had to hound them constantly for payment. It would take six months to a year for us to collect from them, and then they would pay only because they needed to retrieve a box.
That type of customer literally takes money out of your pocket. To begin with, you don’t have the use of the money that the customer owes you and promised to give you when you signed him up. Let’s say his outstanding bill is for $1,000. If he doesn’t pay on time, you have to borrow an extra $1,000 from the bank. Suppose you’re paying 9 percent annual interest on your loans. That’s $90 per year. So your $1,000 is really just $910. Meanwhile, your accounting person is spending half an hour each month calling this guy and listening to his lame excuses and false promises. That’s six hours per year. If you pay the accountant $25 an hour, with benefits figured in, the slow payer costs you an additional $150 annually, meaning that the $1,000 is now down to $760.
Look at what that does to your gross margins. Normally, I would expect an account that small to have a gross margin of at least 40 percent. It wouldn’t be worth accepting the business for less, even if the guy paid on time. So, on $1,000, you should be earning a gross profi t of $400. But because he takes a year to pay—and makes you spend $260 on interest and labor that you wouldn’t have to spend otherwise—your gross profit is $140. That’s a 14 percent gross margin. I don’t know about you, but if we had too many accounts like that, we’d be out of business! I don’t want or need that kind of customer, and so we made those accounts pay up or leave."
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Trecho retirado de "The Knack - How Street-Smart Entrepreneurs Learn to Handle Whatever Comes Up" de Norm Brodsky e Bo Burlingham