For more than three decades, Andris Zoltners, now an emeritus professor at Northwestern, has been studying the best ways to organize and pay salespeople. The pioneer of sales analytics, he is the founder of one of the world's largest sales consulting firms and the author of six books on sales management. In this interview, he shares some of his insights with HBR. Companies make several common mistakes with sales compensation, Zoltners notes: over- or underincentivizing key products, setting quotas too high or too low, and underpaying top performers or overpaying people with good territories. Companies often get the proportion of incentive pay wrong, too, because they fail to account for "free sales"--residual sales they get nearly automatically. They may think they're paying 60% in salary and 40% in commissions, but if their salespeople have a lot of free sales, commissions could be closer to 15%. Overly complicated plans are also a problem. Some plans have different payments for dozens of objectives. That's too much; salespeople can focus on only four or five goals at most. Yet a bigger issue may be an overreliance on compensation in the first place, Zoltners suggests. There are other drivers of sales success--the people you hire, their managers, the design of territories. And while analytics are a useful tool, culture may prove to be an even better one.

Although companies devote considerable time and money to managing their sales forces, few focus much thought on how the structure of the sales force needs to change over the life cycle of a product or a business. However, the organization and goals of a sales operation have to evolve as businesses start up, grow, mature, and decline if a company wants to keep winning the race for customers. Specifically, firms must consider and alter four factors over time: the differing roles that internal salespeople and external selling partners should play, the size of the sales force, its degree of specialization, and how salespeople apportion their efforts among different customers, products, and activities. These variables are critical because they determine how quickly sales forces respond to market opportunities, influence sales reps' performance, and affect companies' revenues, costs, and profitability. In this article, the authors use time-series data and cases to explain how, at each stage, firms can best tackle the relevant issues and get the most out of their sales forces. During start-up, smart companies focus on how big their sales staff should be and on whether they can depend on selling partners. In the growth phase, they concentrate on getting the sales force's degree of specialization and size right. When businesses hit maturity, companies should better allocate existing resources and hire more general-purpose salespeople. Finally, as organizations go into decline, wise sales leaders reduce sales force size and use partners to keep the business afloat for as long as possible.