By day I’m a writer, but few people know that I also have a side hustle. I love to comb thrift stores on weekends, looking for items to flip on eBay. My latest score was a beautiful pair of Alden Shoes that I picked up for $20 at the Salvation Army and will sell for about $200. I also stumbled upon three copies of Newsweek’s “Madam President” edition ( which was quickly recalled ) at my local Target. They sold in less than 24 hours for more than ten times what I paid.

A side job can be fun and put a little extra money in your pocket in the process, or it can allow you to pursue a passion. David Mulqueen is a project manager for Odd Dog Media, a Seattle-based digital marketing agency, but on nights and weekends, he runs Seattle Snowboard Instructor.

“Snowboarding is my passion, and I love teaching others how to snowboard,” he says. “I want others to stop hating winter and open up new hobbies to people so they can begin to appreciate all of the seasons our world has to offer.”

A growing number of people are finding that two jobs are better than one. Adobe’s “Future of Work” study found that one third of over 1,000 U.S. workers currently hold two or more jobs. A different report by CareerBuilder found 29% of more than 3,200 workers have a second job. The trend is hotter among millennials, 44% of whom hold multiple jobs.

CareerBuilder’s findings indicate that side gigs are most popular for people who work in leisure and hospitality industries (34% do), with retail and transportation coming in second and third. And the most popular extra jobs include survey taker, childcare provider, consultant, freelance writer, blogger, bartender, photographer, website designer, and tutor.

While side jobs can provide a nice amount of extra money, workers of all income levels are taking on side work, according to CareerBuilder. Nearly one in five make more than $75,000 a year in their regular job, and 12% earn more than six figures.

In the Adobe study, 88% of respondents admitted they work for their paycheck, but 60% also do it for recognition and just over half (51%) believe their side work has social impact. The bonus is that 78% of those workers surveyed believe that moonlighting has made them happier and more optimistic.