The minute you spend a dollar of your own money providing your customers with goods or services, you are effectively investing your own money in their business. A good investment is one that both makes you money and preserves your capital. When you invest money in shares or property, you take precautions to make sure your money is safe and the returns are right. And so you should too when you invest in your customers’ business.
Your chances of recovering that investment – and your profit - on a timely basis are usually pre-determined by what precautions you take before you invest the money, not after.