Pitbull and Richard Branson agree on this key ingredient for success

To be successful, you need grit, resilience and the resolve to put in as many hours as necessary to get the job done.

But the recipe for success isn't all hard work: It also demands a hefty dose of fun, something recommended by both billionaire entrepreneur Richard Branson and Grammy-winning recording artist Pitbull.

"Fun is one of the most important — and underrated — ingredients in any successful venture," Branson writes in "The Virgin Way: Everything I Know About Leadership." "If you're not having fun, then it's probably time to call it quits and try something else."

Branson launched his first company, Student magazine, at age 15. Since then, he's overseen approximately 500 different ventures, hundreds of which still live under the Virgin umbrella.

Fun has been a key tenet of Virgin from the start. "Anyone who has followed the Virgin story knows that our company culture has driven our success," Branson writes on his blog.

At the beginning, money was tight and Branson would have to carefully go over the books each week to determine if he could continue to afford rent and payroll. But this pressure didn't deter Virgin's staff: "We were having such a great time that we kept going, mostly because we just liked hanging out together," Branson writes.

The concept of having fun also drove some of Branson's most successful businesses. When he went to the CEOs of Virgin Music with the idea of using a third of the company's profits to start an airline because he believed it would be "fun," they weren't entirely on board, Business Insider reports. But Branson persisted and Virgin Atlantic, one of the company's most well-known properties, was born.

For Pitbull, enjoying what you do is crucial to sustaining success. Without it, burnout is imminent.

"The best advice I could possibly give you is that you've got to have fun," he told the audience at the eMerge Americas conference in Miami, Fla. "You've got to be happy. You never want to have a billion-dollar business to have a trillion-dollar headache. If there's any one person out there I know that is miserable, most of them are billionaires. They forgot how to have fun!"

Growing up poor in Miami with a single mother, Pitbull didn't always have the most enjoyable childhood. But it was interesting: He realized the power of words as a five-year-old when his father would make him recite poems in bars. He fell in love with music at age 13, later turning it from a hobby into a career.

Now, the best-selling rapper uses music as a vessel for his personal expression. "Music is my platform, it's my avenue," he says.

Even though he works hard, making music is never a chore for Mr. Worldwide, which only aides in his success. He emphasizes that "in your journey on whatever you guys are trying to create, there's no magic bullet, magic formula, cutting corners, or cheating," but passion pays off.

"You're going to fall, you're going to fail, you're going to lose — and that becomes fun," he says.

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