When the new head of sales for a large, publicly-traded firm delivered his first all-company address, his 33-minute presentation was interrupted by applause thirty-five times. I had worked with him weeks ahead of time to craft a presentation that would elicit a high level of engagement.

We used one of the oldest psychological tools in the leadership basket–praise. We chose about 30 individuals to praise for specific reasons. They were asked to stand, and their photos were shown on the screen. Their faces were beaming, and the audience loved it.

Cognitive and behavioral psychologists say we are hardwired for social recognition even more than we might realize. Duke psychologist Dan Ariely calls positive recognition “a kind of human magic.” If you can tap into the deep-seated need to be praised and recognized for our achievements, you’ll be the kind of leader who attracts, retains, and motivates star employees. Best of all, it’s free.

Based on my research and interviews with leaders at some of the world’s best places to work, I’ve found that praising an individual’s achievement does boost engagement and, by extension, customer satisfaction and profits. But for praise to be valuable it must be personal, purposeful, and public. 

1. Make praise personal.

“Always look for the best in your people,” says Virgin founder Richard Branson. “Lavish praise and people will flourish; criticize and they’ll shrivel up.” Branson makes praise personal. I had the opportunity to spend a day with Branson when he was promoting new routes for Virgin America (which has since been sold to Alaska Airlines). Branson takes every opportunity to personally appear at team celebrations. He believes that praising people with a small, impromptu party or celebration has the power to raise morale and reinforce positive behaviors.

Branson looks for what people do right, not what they do wrong. He calls employees personally to thank them for a job well done. He’ll send a text to a manager to share with a team that did something exceptional to improve the passenger experience.

Yes, it’s important to lavish praise on people, and Branson goes out of his way to personally recognize even the smallest efforts.

2. Make praise purposeful.

Praise makes people feel good, which is a worthy outcome. But for praise to elevate a brand, it must have a purpose behind it. Simply saying “good job” to an associate does not advance your brand’s overall mission or values.

This year, Wegmans Food Markets was named the second best place to work in the country, second only to Salesforce. Employees cite the “love and caring” atmosphere they feel when they go to work. Dig a little deeper and you’ll find that employees are motivated by rewards–and not necessarily cash rewards.

At Wegmans, reward programs are focused on thanking people for very specific accomplishments that reinforce the brand’s values, such as anniversaries (loyalty), reaching development goals (learning), and helping others (service). Employees can also reward colleagues with $5 coupons, which they can use at the store. The coupons are handed out to colleagues who “live the company values.”

At Wegmans, praise has a purpose.

3. Make praise public.

Economists and psychologists have found that local fame is a powerful social motivator. Local fame simply means that people are recognized in front of their peers, family, or friends.

Southwest Airlines maintains its popular culture by providing employees with praise–made public. Every week in the form of a company-wide email, CEO Gary Kelly gives sends a “shout out”–public praise–to employees who have gone above and beyond to deliver great customer service.

Each month, Southwest’s Spirit magazine features the story of an employee who has gone above and beyond, along with stories and videos on the company Intranet. Finally, frequent flyers are mailed Kick Tail coupons, which they can hand to employees who go above and beyond. A smile or a friendly attitude often results in a coupon. Employees who receive coupons are entered in monthly and yearly drawings for prizes where, once again, they’re recognized publicly.

Every year for the past 18 years, the Gallup organization has released its annual report of employee engagement, and every year tells a similar story. This year, a full 87 percent of employees say they are “not engaged” in their work. One of the key questions they’re asked: “In the last seven days, have you received recognition or praise for doing good work?” Gallup says this question is one of the best predictors of workgroup performance.

Year after year, most employers fall short. Don’t be one of them. Praise and recognition is the single most powerful motivator you’re not using nearly as much as should.