There's an old sales adage that goes something like this: People do business with people they know, like and trust. On the surface, that statement can seem like one of those tired platitudes floating around on social media. After all, isn't it common sense that you would want to buy from people you like and trust? But, as another popular saying goes, 'Common sense is not common practice.'

For examples of this, look no further than organizations like The Weinstein Company, Uber and Wynn Resorts (to name a few) where allegations of not-so-nice behaviors have virtually crippled the companies. In such cases, it's plain to see how common sense really isn't common practice.

So when I heard author and businesswoman Bobbi Brown credit friendliness to her success -- as well as, no doubt, lots of elbow grease -- well, that made lots of sense.

Like many people, I've had my fair share of bad experiences with companies that have left me feeling angry and deflated. I've also had my fair share of terrific experiences with companies who've made it clear they valued my business and cared about my opinions; not surprisingly, it makes me want to keep doing business with those companies.

In her interview with Inc. staff at the 2017 Iconic Tour in New York, the cosmetics mogul shared how she founded a company with one lipstick and grew it into an international sensation with thousands of employees and millions in revenue on a simple premise: be nice to people.

"It's common sense," Brown told the audience. "Don't do it because you want something. (Do it because) it actually makes you feel good."

To foster a feel-good company culture, in the beginning, Brown said, she hosted employee holiday parties at her house, held special events for makeup artists and created a "healthy kitchen" for employees. "We did what we could," she explained. "It's just about, 'How do you make a culture that you believe in?"

Brown may look like a pollyanna but being nice to people, it turns out, not only makes you feel good, it's also good for business. Being nice to people, one study shows, breeds trust, cooperation, and higher productivity -- qualities that bode well for both companies and their consumers. It's not surprising, then, that Brown inspired loyalty among employees and customers alike.

At a conference on compassion and business at Stanford University, researchers noted that a culture of kindness and caring begets more kindness and caring. Similarly, a toxic culture filled with criticism and stress begets more of the same.

"The research on emotional contagion shows that people are particularly likely to catch the emotions of their leaders," George Mason University School of Management assistant professor Olivia (Mandy) O'Neill tells science journalist Marina Krakovsky. "Unfortunately, people in power tend to be the worst at taking the perspective of others."

Yale University researcher David Rand has been studying the "behavioral economics of niceness" at his Human Cooperation Lab at Yale. Rand's studies show that it's more effective to be cooperative than not, despite the old -- and persistent -- myth that "nice guys finish last."

"When you have one-off interactions with someone, then it's in your self-interest to take advantage of them," Rand explains in this interview in The Atlantic. But when you have to work with people on a regular basis, then it's in everyone's best interest to be cooperative.

"In an uncertain world, fairness finishes first," he says.

No doubt, the research is clear: kindness is important in the workplace because a culture of compassion and kindness leads to greater productivity and greater contributions from team members and workers.

So take Bobbi Brown's lead and just be nice to people.