This article originally appeared on HBR.org (subscription may be required).

You have great loyalty scores and low customer churn. But sales are flat—or worse, falling. What’s going on? In most cases, this happens because you’ve failed to capture the economic potential of the goodwill in your customer base.

Low churn and high loyalty scores usually mean that customers feel good about your company. They like doing business with you. They’re inclined to stay longer, buy more and tell their friends about their good experiences. Great! But the economic benefit comes only when customers act on those feelings—and companies can make it easier or harder for them to do so. Here are three ways to transform loyalty into bottom-line results:

Learn more about your most loyal customers. Most companies work hard to determine the root causes of customer dissatisfaction. But it’s equally important to determine the sources of customer delight. If customers are happy because of product quality, what do they cite as evidence? If their delight stems mostly from their buying experience, what was it about the process that most impressed them? Converting feelings into action requires knowing exactly what you did to earn their loyalty, so you can replicate the action and extend it.

To maintain that kind of intimate relationship with your most loyal customers, you have to create effective mechanisms for staying in close touch. The Vanguard Group, for example, makes a point of interviewing a sample of clients who have convinced others to bring business to the firm. The company asks these clients how they came to be so enthusiastic about Vanguard and what it was that they told the other person. Most of these customers, Vanguard discovered, had experienced an unusual “moment of truth” in their dealings with the company, such as receiving extra help after the death of a spouse or the birth of a child.

Tune your offerings to meet their needs. Getting to know your most loyal customers will likely reveal both strengths and weaknesses in your product line. It may show you that competitors are offering something that you aren’t. It may uncover customers’ unmet needs—which they can’t quite articulate. Ideally, your offerings should be so attractive to your loyalists that they have no reason to look elsewhere for additional products or services.

Nearly every company can find ways to tune its offerings to meet customers’ needs more completely. Banks have developed smartphone apps to enable instant deposits and other forms of self-service—both delighting customers and also allowing branch staff to concentrate less on routine transactions and more on providing the higher-touch personal services their best customers value. Some utilities help customers finance, install and maintain their own systems for generating power and heat through solar roof panels. Others help their commercial and industrial customers maintain small, decentralized generating units.

By tailoring these products and services to fit perfectly into their customers’ lives, these companies make it easier for their happy customers to buy more and stay longer.

Help them spread the word. When there’s a drum-tight fit between what you offer and what your best customers want, you’ll want to help them sing your praises. Provide them with the kind of stories they will actually tell to friends, giving those friends a reason to buy from you.

Those stories might come from mundane, everyday service. The employees of FirstService Residential, a property management company, glean interesting anecdotes, and create tiny pools of goodwill, when they take the time to open doors and carry groceries for residents. Or, stories might reflect exceptional service in a crisis—like the time I tweeted my dismay about my flight being rescheduled, and suddenly got a call from a JetBlue representative.

If your customers don’t already have a good one, you also want to provide them with a platform they can use to tell their stories to a relevant audience. These platforms can take the form of online communities, such as Adobe Marketplace & Exchange Classic, or real-world communities, such as LEGO user groups. They can also take the form of references, video testimonials and so on—particularly useful in a business-to-business context.

High rates of loyalty are a huge asset in business. They provide a necessary foundation for profitable growth. But that growth doesn’t happen automatically—your company needs to make it easy for your customers to do more business with you and to bring their friends. The steps outlined here should help you convert loyalty into great performance.

Rob Markey is co-author of the book The Ultimate Question 2.0: How Net Promoter Companies Thrive in a Customer-Driven World (HBR Press). Markey is a partner and director in Bain & Company’s New York office and leads the firm’s Global Customer Strategy and Marketing practice.