In certain businesses with limited competition or long-term contracts, executives can easily delude themselves into thinking they have captive customers. They might even be partly right: Many of their customers may use their services without complaint and accept the automatic deductions flowing out of their checking accounts.

That is, until a major disruptive trend shatters this fantasy. And that always happens.

Think about utilities. A century and a half ago, most gas companies had profitable businesses providing lighting to homes and businesses. Then Thomas Edison hit the scene with a centralized electrical power plant in 1882. Gas companies didn't just lose their lock on their customers, they had to rethink their entire business model. When was the last time you turned on your living room lights with a match?

Today, it’s Edison’s centralized model that’s being turned upside down. Increasingly, customers can choose how their electricity is generated—or make it themselves. It’s also happening in media as online streaming threatens the reach of cable companies, and in telecommunications where phone service providers must compete with Skype and Internet-based communication tools.

Even if you think your customers have no alternative to your services (and trust me, they’ll find one eventually), their loyalty matters. No penalty, fee or rule is enough to keep a subscriber who is truly fed up. And until they find a way out, those detractors will cost your company, because they will share their misery, tie up your call centers and demoralize your employees.

That’s why loyalty matters—no matter what your business. Asking your customers how likely they would be to recommend your services to their friends and family will tell you a lot about what you can do to earn that loyalty—and how your company will fare when the inevitable disruption occurs.