One of the most important business principles is to track not only how much you make, but how much you keep after expenses. To illustrate this point, I was once at a conference where the speaker said that he made $1 million in commissions. When he was asked about his marketing budget, he said he spent $950,000. Needless to say, this agent wasn’t managing his resources well.

To avoid falling into this trap, limit your total marketing budget to 10 percent of your gross commissions. If your income increases, you can spend more. If it decreases, cut back. This simple approach is one of the smartest ways to keep your business profitable.