The One Number You Need to Grow

by Frederick F. Reichheld

The survey was different in another important way. In ranking the branches, the company counted only the customers who gave the experience the highest possible rating. That narrow focus on enthusiastic customers surprised the CEOs in the room. Hands shot up. What about the rest of Enterprise’s customers, the marginally satisfied who continued to rent from Enterprise and were necessary to its business? Wouldn’t it be better to track, in a more sophisticated way, mean or median statistics? No, Taylor said. By concentrating solely on those most enthusiastic about their rental experience, the company could focus on a key driver of profitable growth: customers who not only return to rent again but also recommend Enterprise to their friends.

Enterprise’s approach surprised me, too. Most customer satisfaction surveys aren’t very useful. They tend to be long and complicated, yielding low response rates and ambiguous implications that are difficult for operating managers to act on. Furthermore, they are rarely challenged or audited because most senior executives, board members, and investors don’t take them very seriously. That’s because their results don’t correlate tightly with profits or growth.

But Enterprise’s method—and its ability to generate profitable growth through what appeared to be quite a simple tool—got me thinking that the company might be on to something. Could you get similar results in other industries—including those seemingly more complex than car rentals—by focusing only on customers who provided the most enthusiastic responses to a short list of questions designed to assess their loyalty to a company? Could the list be reduced to a single question? If so, what would that question be?

It took me two years of research to figure that out, research that linked survey responses with actual customer behavior—purchasing patterns and referrals—and ultimately with company growth. The results were clear yet counterintuitive. It turned out that a single survey question can, in fact, serve as a useful predictor of growth. But that question isn’t about customer satisfaction or even loyalty—at least in so many words. Rather, it’s about customers’ willingness to recommend a product or service to someone else. In fact, in most of the industries that I studied, the percentage of customers who were enthusiastic enough to refer a friend or colleague—perhaps the strongest sign of customer loyalty—correlated directly with differences in growth rates among competitors.

''By substituting a single question for the complex black box of the typical customer satisfaction survey, companies can actually put consumer survey results to use and focus employees on the task of stimulating growth''.

Certainly, other factors besides customer loyalty play a role in driving a company’s growth—economic or industry expansion, innovation, and so on. And I don’t want to overstate the findings: Although the “would recommend” question generally proved to be the most effective in determining loyalty and predicting growth, that wasn’t the case in every single industry. But evangelistic customer loyalty is clearly one of the most important drivers of growth. While it doesn’t guarantee growth, in general profitable growth can’t be achieved without it.

Furthermore, these findings point to an entirely new approach to customer surveys, one based on simplicity that directly links to a company’s results. By substituting a single question—blunt tool though it may appear to be—for the complex black box of the typical customer satisfaction survey, companies can actually put consumer survey results to use and focus employees on the task of stimulating growth.

Loyalty and Growth

Before I describe my research and the results from a number of industries, let’s briefly look at the concept of loyalty and some of the mistakes companies make when trying to measure it. First, a definition. Loyalty is the willingness of someone—a customer, an employee, a friend—to make an investment or personal sacrifice in order to strengthen a relationship. For a customer, that can mean sticking with a supplier who treats him well and gives him good value in the long term even if the supplier does not offer the best price in a particular transaction.

Consequently, customer loyalty is about much more than repeat purchases. Indeed, even someone who buys again and again from the same company may not necessarily be loyal to that company but instead may be trapped by inertia, indifference, or exit barriers erected by the company or circumstance. (Someone may regularly take the same airline to a city only because it offers the most flights there.) Conversely, a loyal customer may not make frequent repeat purchases because of a reduced need for a product or service. (Someone may buy a new car less often as he gets older and drives less.)

True loyalty clearly affects profitability. While regular customers aren’t always profitable, their choice to stick with a product or service typically reduces a company’s customer acquisition costs. Loyalty also drives top-line growth. Obviously, no company can grow if its customer bucket is leaky, and loyalty helps eliminate this outflow. Indeed, loyal customers can raise the water level in the bucket: Customers who are truly loyal tend to buy more over time, as their incomes grow or they devote a larger share of their wallets to a company they feel good about.

And loyal customers talk up a company to their friends, family, and colleagues. In fact, such a recommendation is one of the best indicators of loyalty because of the customer’s sacrifice, if you will, in making the recommendation. When customers act as references, they do more than indicate that they’ve received good economic value from a company; they put their own reputations on the line. And they will risk their reputations only if they feel intense loyalty. (Note that here, too, loyalty may have little to do with repeat purchases. As someone’s income increases, she may move up the automotive ladder from the Hondas she has bought for years. But if she is loyal to the company, she will enthusiastically recommend a Honda to, say, a nephew who is buying his first car.)

The tendency of loyal customers to bring in new customers—at no charge to the company—is particularly beneficial as a company grows, especially if it operates in a mature industry. In such a case, the tremendous marketing costs of acquiring each new customer through advertising and other promotions make it hard to grow profitably. In fact, the only path to profitable growth may lie in a company’s ability to get its loyal customers to become, in effect, its marketing department.

The Wrong Yardsticks

Because loyalty is so important to profitable growth, measuring and managing it make good sense. Unfortunately, existing approaches haven’t proved very effective. Not only does their complexity make them practically useless to line managers, but they also often yield flawed results.

The best companies have tended to focus on customer retention rates, but that measurement is merely the best of a mediocre lot. Retention rates provide, in many industries, a valuable link to profitability, but their relationship to growth is tenuous. That’s because they basically track customer defections—the degree to which a bucket is emptying rather filling up. Furthermore, as I have noted, retention rates are a poor indication of customer loyalty in situations where customers are held hostage by high switching costs or other barriers, or where customers naturally outgrow a product because of their aging, increased income , or other factors. You’d want a stronger connection between retention and growth before you went ahead and invested significant money based only on data about retention.

An even less reliable means of gauging loyalty is through conventional customer-

satisfaction measures. Our research indicates that satisfaction lacks a consistently

demonstrable connection to actual customer behavior and growth. This finding is borne out by the short shrift that investors give to such reports as the American Consumer Satisfaction Index. The ACSI, published quarterly in the Wall Street Journal, reflects the customer satisfaction ratings of some 200 U.S. companies. In general, it is difficult to discern a strong correlation between high customer satisfaction scores and outstanding sales growth. Indeed, in some cases, there is an inverse relationship; at Kmart, for example, a significant increase in the company’s ACSI rating was accompanied by a sharp decrease in sales as it slid into bankruptcy.

Even the most sophisticated satisfaction measurement systems have serious flaws. I saw this firsthand at one of the Big Three car manufacturers. The marketing executive at the company wanted to understand why, after the firm had spent millions of dollars on customer satisfaction surveys, satisfaction ratings for individual dealers did not relate very closely to dealer profits or growth. When I interviewed dealers, they agreed that customer satisfaction seemed like a reasonable goal. But they also pointed out that other factors were far more important to their profits and growth, such as keeping pressure on salespeople to close a high percentage of leads, filling showrooms with prospects through aggressive advertising, and charging customers the highest possible price for a car.

In most cases, dealers told me, the satisfaction survey is a charade that they play along with to remain in the good graces of the manufacturer and to ensure generous allocations of the hottest-selling models. The pressure they put on salespeople to boost scores often results in postsale pleading with customers to provide top ratings—even if they must offer something like free floor mats or oil changes in return. Dealers are usually complicit with salespeople in this process, a circumstance that further degrades the integrity of these scores. Indeed, some savvy customers negotiate a low price—and then offer to sell the dealer a set of top satisfaction survey ratings for another $500 off the price.

Figuring out a way to accurately measure customer loyalty and satisfaction is extremely important. Companies won’t realize the fruits of loyalty until usable measurement systems enable firms to measure their performance against clear loyalty goals—just as they now do in the case of profitability and quality goals. For a while, it seemed as though information technology would provide a means to accurately measure loyalty. Sophisticated customer-relationship-management systems promised to help firms track customer behavior in real time. But the successes thus far have been limited to select industries, such as credit cards or grocery stores, where purchases are so frequent that changes in customer loyalty can be quickly spotted and acted on.

Getting the Facts

So what would be a useful metric for gauging customer loyalty? To find out, I needed to do something rarely undertaken with customer surveys: Match survey responses from individual customers to their actual behavior—repeat purchases and referral patterns—over time. I sought the assistance of Satmetrix, a company that develops software to gather and analyze real-time customer feedback—and on whose board of directors I serve. Teams from Bain also helped with the project.

We started with the roughly 20 questions on the Loyalty Acid Test, a survey that I designed four years ago with Bain colleagues, which does a pretty good job of establishing the state of relations between a company and its customers. (The complete test can be found at http://www.loyaltyrules.com/loyaltyrules/acid_test_customer.html.) We administered the test to thousands of customers recruited from public lists in six industries: financial services, cable and telephony, personal computers, e-commerce, auto insurance, and Internet service providers.

We then obtained a purchase history for each person surveyed and asked those people to name specific instances in which they had referred someone else to the company in question. When this information wasn’t immediately available, we waited six to 12 months and gathered information on subsequent purchases and referrals from those individuals. With information from more than 4,000 customers, we were able to build 14 case studies—that is, cases in which we had sufficient sample sizes to measure the link between survey responses of individual customers of a company and those individuals’ actual referral and purchase behavior.

The data allowed us to determine which survey questions had the strongest statistical correlation with repeat purchases or referrals. We hoped that we would find at least one question for each industry that effectively predicted such behaviors, which can drive growth. We found something more: One question was best for most industries. “How likely is it that you would recommend [company X] to a friend or colleague?” ranked first or second in 11 of the 14 cases studies. And in two of the three other cases, “would recommend” ranked so close behind the top two predictors that the surveys would be nearly as accurate by relying on results of this single question. (For a ranking of the best

So my colleagues and I had the right question—“How likely is it that you would recommend [company X] to a friend or colleague?”—and now we needed to develop a scale to score the responses. This may seem somewhat trivial, but, as statisticians know, it’s not. Making customer loyalty a strategic goal that managers can work toward requires a scale as simple and unambiguous as the question itself. The right one will effectively divide customers into practical groups deserving different attention and organizational responses. It must be intuitive to customers when they assign grades and to employees and partners responsible for interpreting the results and taking action. Ideally, the scale would be so easy to understand that even outsiders, such as investors, regulators, and journalists, would grasp the basic messages without needing a handbook and a statistical abstract.

For these reasons, we settled on a scale where ten means “extremely likely” to recommend, five means neutral, and zero means “not at all likely.” When we examined customer referral and repurchase behaviors along this scale, we found three logical clusters. “Promoters,” the customers with the highest rates of repurchase and referral, gave ratings of nine or ten to the question. The “passively satisfied” logged a seven or an eight, and “detractors” scored from zero to six.

By limiting the promoter designation to only the most enthusiastic customers, we avoided the “grade inflation” that often infects traditional customer-satisfaction assessments, in which someone a molecule north of neutral is considered “satisfied.” (This was the danger that Enterprise Rent-A-Car avoided when it decided to focus on its most enthusiastic customers.) And not only did clustering customers into three categories—promoters, the passively satisfied, and detractors—turn out to provide the simplest, most intuitive, and best predictor of customer behavior; it also made sense to frontline managers, who could relate to the goal of increasing the number of promoters and reducing the number of detractors more readily than increasing the mean of their satisfaction index by one standard deviation.

The Growth Connection

All of our analysis to this point had focused on customer survey responses and how well those linked to customers’ referral and repurchase behavior at 14 companies in six industries. But the real test would be how well this approach explained relative growth rates for all competitors in an industry—and across a broader range of industry sectors.

''The only path to profitable growth may lie in a company’s  ability to get its loyal customers to become, in effect, its marketing department''.

In the first quarter of 2001, Satmetrix began tracking the “would recommend” scores of a new universe of customers, many thousands of them from more than 400 companies in more than a dozen industries. In each subsequent quarter, they then gathered 10,000 to 15,000 responses to a very brief e-mail survey that asked respondents (drawn again from public sources, not Satmetrix’s internal client customer lists) to rate one or two companies with which they were familiar. Where we could obtain comparable and reliable revenue-growth data for a range of competitors, and where there were sufficient consumer responses, we plotted each firm’s net promoters—the percentage of promoters minus the percentage of detractors—against the company’s revenue growth rate.

The results were striking. In airlines, for example, a strong correlation existed between net-promoter figures and a company’s average growth rate over the three-year period from 1999 to 2002. Remarkably, this one simple statistic seemed to explain the relative growth rates across the entire industry; that is, no airline has found a way to increase growth without improving its ratio of promoters to detractors. That result was reflected, to a greater or lesser degree, in most of the industries we examined—including rental cars, where Enterprise enjoys both the highest rate of growth and the highest net-promoter percentage among its competitors. (See the exhibit “Growth by Word of Mouth.”)