If you’re tired of waiting around for a raise, here’s an option for taking matters into your own hands. Consider the side hustle:  a way to make extra money, boost your savings and widen your horizons. 

Nearly four in 10 Americans (37%) have a side hustle, according to a new report from Bankrate.com, whether it’s driving for Lyft, waiting tables on the weekends or selling handmade items on Etsy.

What motivates these moonlighters?  Some 38% say it’s to meet regular living expenses; 59% of those who earn money on the side say they want to have more disposable income.  

But while gig work or a second job can bring in extra cash, it’s not just about the money. Diane Mulcahy, author of “The Gig Economy” and an adjunct lecturer at Babson College, says that other reasons can motivate side hustlers.

“They might want to explore whether an idea or a service or a product that they have is a viable business,” Mulcahy told U.S. News & World Report. “Or they might want to explore an area of interest or they might want to gain another skill or expand their network.”

Home repair/landscaping, online sales, crafts and childcare are the most popular side jobs, according to the Bankrate.com report. The median side hustler earns $200 per month, with average earnings around $686 monthly.  Men are seven percentage points more likely than women to earn extra money away from their primary job. The gender pay gap applies to side hustles, too. Men earn an average of $989 from their extra gigs, almost three times the $361 that women earn.

Taking action to earn more is good news, according to Amanda Dixon, a Bankrate.com analyst. In contrast with other surveys that suggest that many Americans aren’t making smart financial decisions, this trend might be a step toward increased financial security. 

“Having more than one source of income is a smart move and having a side gig is a great way to boost your savings and meet other financial goals,” she said. 

Millennials are most likely to have occasional jobs; the odds of someone earning money from side gigs declines with age. Many millennials have good reasons for working for extra cash, too.

“Most millennials — at least on the professional end who have been to college — have significant debt and a lot of them are looking for ways to either build a financial cushion or reduce their debt faster,” Mulcahy said.