Every salesperson knows that not all customers are created equal. Some generate stable business, pay on time, and communicate clearly. Others require excessive attention, place heavy demands on the salesperson, and may even struggle to meet their financial obligations. Having a portfolio composed of high quality and reliable clients is the goal of every salesperson, not least because the less time spent resolving problems, the more time you have for acquiring new business opportunities. Here are four steps to help you build a valued client base over the long term.