Legendary investor Warren Buffett, the founder and CEO of Berkshire Hathaway, shared his best business advice with a group of small business owners.

Speaking at the 20th Graduation of Goldman Sachs’ 10,000 Small Businesses at LaGuardia Community College, Buffett told the graduates: “Tomorrow morning when you look in the mirror after you’ve gotten up, just write — or just put it in lipstick or whatever you want — ‘delight my customer' not 'satisfy my customer.’ ‘Delight my customer.’”

It's a simple three-word mission.

He continued: “Any business that has delighted customers has a salesforce out there that you don’t have to pay. You don’t see them, but they are talking to people all the time.”

Buffett was referring to those delighted customers.

He used an example of when he bought his last car. He doesn’t remember how much he paid for it, but he does remember the experience.

“Your customer is going to get to vote, going to talk, and you want them out there as salesmen for you and they will be if you delight them.

According to Buffett, the “classic example” is Jeff Bezos, the founder of Amazon. Bezos started Amazon in his garage in his early 30s.

“Bezos set out every day to delight his customer by fast delivery, by lower prices, whatever it took,” Buffett said. "And today, he is thinking about how to delight his customer."

“Don’t ever quit. You’ll succeed if you have delighted customers. Don’t settle for satisfied. Have that person thinking ‘I’ve never had a better experience with a human being’ and they’ll be back to buy your product.”

Buffett was joined by Jack Dorsey, cofounder and CEO of Square and Twitter; Lloyd Blankfein, CEO of Goldman Sachs; and Michael Bloomberg, the founder of Bloomberg LP and former New York City Mayor.

10,000 Small Businesses is a program created through a partnership between Goldman Sachs and LaGuardia Community College that aims to help entrepreneurs grow their businesses and create jobs by providing access to education, capital, and technical assistance.

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Julia La Roche is a finance reporter at Yahoo Finance.

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be located on the LaGuardia Community College campus.