A smile signals hope, and hope is in short supply. Smiles also signal confidence, which translates into credibility, which invites trust, which fosters influence. Even National Geographic ran a story on The Power of a Smile, featuring photos of irresistible grins from around the world—because “smiles are universal.”

So, does that mean you should start smiling like the Cheshire Cat in Alice in Wonderland? Not necessarily—definitely not if long-term relationships are your goal. The Cheshire Cat was shady and dark behind that permanent smile. The world is dauntingly full of Cheshire Cat smiles that make people want to run and hide.

Whether you’re an individual or an organization, your smile must be genuine if you want to build relationships that last. Marketing analytics blogger James T. Noble says, “This is a trend which is not going away. An open and trustworthy business is a popular business, whereas charlatan companies will ultimately fail regardless of whatever efforts are made to promote them and however much money is invested in them.” In other words, even the “Lizzes” of the world eventually lose their customers if they smile too big and too long about the wrong kinds of things.

If I asked you to name companies that smile, certain brands would probably pop into your head. That’s because brands have personalities. We view them in much the same way we view people, and we build person-like relationships with them as well. It follows, then, that if we like people who smile, we also like companies that smile. But what does that even mean?

A smile communicates gratefulness.

Systematic gratefulness is much more effective than giving Christmas bonuses when it comes to generating employee satisfaction and loyalty. That’s how employees see it, and that perspective plays out in how they represent the company to customers. First and foremost, companies that smile recognize the inherent value of good employees and express thankfulness in countless ways for their contribution to the bottom line.

Companies have faces, and for customers the company face is often the face of the last employee they interacted with. Employees emanate either the joy or the misery of the company culture they work in day after day. If your employees aren’t smiling, chances are your company isn’t either. And that may be one of the reasons customers take their business elsewhere.

Companies that smile have figured out how to make their employees smile—by encouraging them on a personal level, paying them well, providing them with a great working environment, challenging them with interesting projects, and giving them the training they need to function well and feel good about their work performance and contribution to company goals. Employees are your first and most important customers. If your employees aren’t happy, your customers aren’t happy either.

The contribution of happy, satisfied employees to the company bottom line is significant. Alex Edmans, finance professor at the Wharton School of Business, discovered that public firms onFortune’s list of 100 Best Companies to Work For outperform industry peers by two to three percent in terms of annual stock market growth, and also beat analyst expectations for quarterly earnings in countries with high labor market flexibility (i.e., where people have labor choices). Some companies like Amazon and Zappos even pay unhappy employees to quit.

A smile communicates generosity.

I’m not talking about traditional corporate charity with an eye for getting something in return, nor am I talking about companies performing generous acts merely to generate brand awareness and positive buzz. I’m talking about companies that weave generosity and social responsibility into the fabric of their organizational mission. Millennials are leading the way in this area. Take, for instance, Sevenly, which donates $7 to various designated charities for every item it sells. In its own words, “Sevenly exists to bring funding and awareness to the world’s greatest causes.”

Why is generosity an important aspect of a company smile? Generosity indicates not only that change is possible (i.e., there’s hope), but also that the company has both the desire and the power to make it happen. Where there’s hope, there’s reason to smile. If a company has time and resources to dedicate to generous pursuits, then it’s also likely to be profitable. Customers recognize a going concern when they see one. Generosity indicates a concern that is actually going somewhere, and customers are interested in going along for the ride.

Unlike my young nephews, many customers are mature enough to tell the difference between a company that performs a generous act as part of a profit-driven marketing strategy and one that eagerly brings generosity to society’s table in return for the privilege of remaining profitable. That leads to the third G.

A smile communicates credibility.

In the ever-changing but predictable world of customer expectations, genuineness means consistency between representation and actual experience. It means that a company’s apparent attributes are its actual attributes. It also means that those attributes can be experienced by customers in the same wonderful way from one day to the next, with one employee to the next, and in one location to the next. It’s that consistency of experience by which many customers define—and are willing to pay for—core value.

These days, authenticity isn’t a luxury. It’s a necessity. In one revealing click, a brand or company can be brought to its knees and permanently humbled. The worst stumbles become fodder for business ethics textbook case studies and are never forgotten.

People build long-term relationships with people they can trust. They do the same with brands and companies. Customers equate authenticity with brand equity and product quality. It’s the key to competitive differentiation. There’s really no need to worry that everyone’s going to start doing it to the point that authenticity will no longer matter. Authenticity will always matter and will remain a hard-to-attain standard.

Genuine brands practice systematic authenticity, as opposed to the transactional type. They respect not only their customers but also their competitors. As authors Amy Jen Su and Muriel Magian Wilkins point out in a Harvard Business Review article, “Authenticity is actually a relational behavior, not a self-centered one. Meaning that to be truly authentic, you must not only be comfortable with yourself, but must also comfortably connect with others.”

How does that translate into a company smile? Honest companies, like honest people, can sleep at night. They have nothing to hide. They don’t have to endure the stress of constantly covering their tracks. They don’t need to engage in defensive behavior. They aren’t stressed out. Customers are their friends, not their enemies. They don’t have any reason not to smile.

A smile builds long-lasting connections.

Viable companies with marketing orientations realize that lasting personal connections are the ultimate goal of all transactions, interactions, and exchanges. On both sides of the exchange, the expectation isn’t just value for value, but rather value plus for value plus. A grateful, generous, genuine company smile adds premium value to its products and services—added value that customers repeatedly seek out and are willing to pay for. That’s just one more thing to genuinely smile about.

Conna Bond is an associate professor of marketing and management and the co-founder of Pineapple Social Media and Red Canoe Creative.