This 34-Year-Old Was 'Wildly Un-Passionate' About His Day Job, So He Started a 9-Figure Side Hustle: 'Be an Animal' Will Nitze asked his boss if he could work half his hours for half the pay in order to build his own business.

It's the era of the side hustle, and if you've ever considered starting one to earn some extra cash outside of your 9-5, you're in good company. These days, more than one-third of U.S. adults have side hustles, and their supplemental gigs make an average of $891 a month, according to recent research from Bankrate. Of course, the most successful side hustlers see much higher earnings, especially when they start a business that brings in nearly as much as — or significantly more than — their full-time sources of income.

Related: This Mom Used an 'Overlooked' Ingredient to Grow a 6-Figure Side Hustle From Her Kitchen: 'Like an Intensive MBA Program'

Miami-based entrepreneur Will Nitze, 34, is one of them. Learn about how Nitze's dissatisfaction with his day job and a light bulb moment inspired him to start his side hustle, which turned into a nine-figure business.