Attrition in any department is costly for a company. It's especially costly when it comes to sales. Can you guess how much US firms spend annually on training salespeople? A whopping $15 billion! Aside from this direct cost, attrition also involves extra time and effort spent on rebuilding client relationships. Managers who can identify top performers that might be at risk for quitting and incentivize them to stay have a distinct advantage over those who cannot, and will save their companies a pretty penny. Check out this article from Harvard Business Review for tips on identifying employees who might be leaving, and when you should/should not try to intervene.