Zach Bohlman had his eye on a used Corvette, but couldn't justify the cost of "a fun summer toy."

So he got behind the wheel of his 2014 Hyundai Elantra and drove for Uber and Lyft. For 18 months, he allocated every penny from his side gig to his summer toy fund.

"I worked weekend nights, picking up the drunk crowd downtown," said Bohlman, 31, whose day job is in insurance arbitration. Even after he got his sports car, he continued to pull the occasional ride share shift.

"It's nice to have a little extra money to blow on stuff that you can't justify spending your real money for," he said. Adding that "the best thing about it is that you work when you want and as long as you want."

In an era of full employment, it's said that every able-bodied worker who wants a job can find one. But an astonishing number of people — many of them with full-time jobs — are pursuing side hustles.

A 2018 survey by Bankrate revealed that 37 percent of Americans trade their time for money with side gigs.

Some pick up cash through the ever-expanding array of internet platforms, logging on and landing on-demand service work — driving, delivering, walking dogs, tutoring, running errands, cleaning or babysitting. Others rely on their creativity and connections to cash in on their marketable skills.

While there have always been temps, moonlighters and freelancers, the sheer number of people involved in what economists call the "contingent labor force" represents a shift in how Americans make a living, according to Sarah Kessler, author of "Gigged: The End of the Job and the Future of Work."

Being able to bring in extra cash is a plus, but it's not clear how well the gig economy is working for workers.

"We're still figuring out what's at stake with this kind of work," she said. "Independent contractors can make decent money, but do they feel secure?"

Gig workers pay a price for the flexibility they enjoy: They're responsible for paying taxes on their income, aren't subject to minimum wage requirements or anti-discrimination laws, get no benefits and can't qualify for overtime or unemployment.

"The fact that supplemental work is a normal expectation by so many people underscores the problem of wage stagnation, too many jobs that don't pay enough to live on," Kessler said.

College, medical bills

The Rev. Zach Wilson wasn't looking to make a living. He has one.

As a career transitional pastor, he steps in to cover ministry needs at churches when a staff pastor has retired or moved on. However, Wilson's hours at these interim assignments vary, and there's sometimes a gap between positions.

A few years ago, he helped manage a writer's social media accounts. Through word of mouth, he got other clients. Now he spends some of his free time doing postings and publicity work, has contracts with a few ongoing clients and advises others for $150 an hour.

"I work for people and causes I believe in, so these connections give me a lot of pleasure and satisfaction," said Wilson, 43, of St. Paul.

Married to another pastor, Wilson allocates half his earnings to household expenses and banks the rest for his two daughters' college funds.

"The income is nice," he said. "If I were more motivated by money I could do better, but then, if I were more motivated by money, I wouldn't be a Presbyterian pastor."

Chellie Bock got her side gig by accident.

A few years ago, the Somerset, Wis., accountant began sharing her photography on her Facebook site, Sunday Mornings (facebook.com/SundayMorningsPhotos/). Her followers (she now has more than 33,000) began buying her work through a fine art site. She also posted about 1,800 images on a stock photography website, from which she earns $30 to $40 a day.

"Photography is my passion and my relaxation and I just wanted to share," said Bock, 52. "I feel so lucky that people find me and want what I do."

Bock, who calls herself "an artist who can balance a checkbook," was socking away her extra earnings for her retirement. But after being diagnosed with breast cancer last year, she's using them to pay costs associated with her treatment.

"I've been healthy, so I have huge deductibles to pay," she said.

Millennials and seniors

Last year, the investment platform Betterment surveyed 1,000 gig economy workers, and found that inadequate savings for retirement prompted a third of the respondents to pursue supplemental work.

"We see huge interest from millennials and seniors; those two groups are uniquely interested in freelance economy," said Kathy Kristof, founder of sidehusl.com.

"It makes sense. Millennials are paying down debt, saving for something like a house or want a life that has more luxuries than what they can afford. A lot of seniors are on fixed incomes, or may have retired and found they still want some work."

Retired nurse Geri Stroud, 77, was having coffee with a few girlfriends when the topic of side hustles came up. Stroud learned that one friend regularly rents out part of her house through a home sharing platform. Another participated in product and medical studies.

Stroud, of Woodbury, decided to augment her Social Security by playing her 30-year-old keyboard in mini-concerts at senior living residences. Last year, she cold-called activity directors at more than 400 facilities to drum up business.

"I'm an old lady and I'm playing for an audience that's even older than me. I give them Big Band songs, classic country, Irish music, Elvis. I can play for five hours without repeating," she said. "I ask $100 an hour but I will work for less."

A gig job "is a winner for me," said Stroud.

While side hustles that allow workers to become low-risk entrepreneurs can be gratifying, it's money — not personal fulfillment — that fuels the search for most gigs. The Betterment survey found that nearly 70 percent of gig workers are motivated to take on their hustle, or a series of them, to cover their living expenses.

"It's a fact that a lot of people who work full time can't and don't make enough to make ends meet," said "Gigged" author Kessler.

Connie Ungrue, 56, of Minneapolis has several gigs going.

"I want several income streams coming in so if I lose a job, I can still earn a living," said Ungrue, who drives for ride-sharing services, does direct sales and social media marketing and also substitute-teaches.

Ungrue lost full-time jobs to budget cuts and when an employer relocated out of state. Her savings took a hit when she divorced. When she couldn't land a traditional position, she cobbled together those gig jobs.

"I haven't cracked the internet application thing," she said. "When I apply online, they say I'm overqualified, but I think it's ageism."

Although Ungrue is not putting anything aside for retirement, her gig work allows her to pay her bills.

Calling herself a go-getter rather than a hustler, Ungrue is not complaining.

"I don't get sick days or holiday pay, but my work is interesting," she said. "I'm the hamster in the wheel, I've got to keep it turning."

Kevyn Burger is a Minneapolis-based freelance broadcaster and writer.