3 Mega-Successful Businesses—Including Two Making Billions—That Started as Side Hustles

Could your side hustle be the next big idea? You never know. These three big-name companies you know were once the founders' side projects.


Could your side hustle be the next big idea? You never know.

Nearly 40 percent of Americans have at least one side hustle while working a 9 to 5 job, according to a 2018 survey from Bankrate. That extra effort pays off to the tune of an extra $8,000 annually.

“You can make extra money on the side right from home,” consumer saving expert Andrea Woroch tells Grow in an email. Several side hustles don’t require idea generating or extended commitments. “For instance, through sites like Rover.com, you can watch other people’s dogs on nights and weekends when you’re home just watching TV and earn up to $1,000 a month.”

Now, not every side project turns into a million-dollar business. But for these three companies whose names you know, it did:

1. Under Armour

Shoppers pass an Under Armour store in White Plains, New York.
Scott Mlyn | CNBC

Some of the most successful businesses are born out of frustration.

In the mid-1990s, Kevin Plank was the special teams captain for the University of Maryland’s football team. Plank was growing tired of getting weighted down by thick, sweaty shirts underneath his jersey. So the student set out to create his own athletic undershirt—one that kept him warm and dry during workouts. He turned his full attention to the idea after graduation, setting up shop in his grandmother’s basement and selling shirts out of his car.

As the clothing line gained traction, Plank’s company—which he dubbed Under Armour—moved into a warehouse and opened its headquarters. In 2018, revenue hit $5.2 billion.

2. WeWork

A man enter the doors of the 'WeWork' co-operative co-working space in Washington, DC.
Mandel Ngan | AFP | Getty Images

You know WeWork as a shared office and living space company. But it started as a way for founder Adam Neumann to make a little extra cash while he was selling baby clothes (called Krawlers, with protective knee pads).

To pinch pennies, Neumann and his cofounder leased some space to collectively work out of, and then developed it into a green coworking hub. They eventually sold their stake in Green Desk—the original name for the company—and used the money to create the WeWork that exists today.

3. Tipsy Elves

Tipsy Elves co-founders Evan Mendelsohn and Nick Morton met in college and are still great friends.
Jeniece Pettitt | CNBC

“We realized in college that it was impossible to find unique, humorous, and one-of-a-kind outfits to wear to the many theme parties we attended,” Tipsy Elves cofounders Evan Mendelsohn and Nick Morton point out on their site.

It was an idea that stayed in the friends’ minds as they went on to grad school and definitively more serious careers—as a lawyer and a dentist, respectively. They began working on Tipsy Elves in their spare time, starting their product line with ugly holiday sweaters. In its first year on the market, Tipsy Elves sold more than 5,000 sweaters. Then came a “Shark Tank” appearance in 2013. Mendelsohn quit his six-figure job one week before he approached the sharks; a risky move that paid off after the cofounders made a deal with Robert Herjavec.

Today the clothing line has sold more than 2 million products, resulting in more than $70 million in sales.

More from Grow: