In the beginning, the entrepreneur starts a company, and does all the selling himself. Then, as the business grows, he hires a salesperson, then a few more salespeople. This goes on for a couple of years, then he hires even more salespeople and a sales manager.
As this progression occurs, this entrepreneur, now the CEO, makes selling mistakes. All CEOs make these mistakes, even if their background was in sales before they started their company, or before they joined the corporation. There aren't many companies run by salespeople; in my experience, CEOs usually come from engineering, finance, or operations. But even the sales-background guys and gals make these same mistakes. Avoiding these seven mistakes can save you a lot of grief.