Collective annual earnings of American gig workers total $1.4 trillion, and 59% use digital marketplaces to find new opportunities, according to the Gig Economy Index released today by PYMNTS and Hyperwallet.

Those aged 18 to 34 rely on digital marketplaces the most, with the arts, design, entertainment, sports and media space being the most prevalent. More than 55% of gig workers rely on a single entity to help them find gigs, and nearly half are very or extremely satisfied with the service. Research respondents listed real-time client identification as the most important benefit of using a digital marketplace such as Upwork or Elance, and the attractiveness of immediate payment availability correlates as well.

As many as 60% of the gig workers surveyed reported they would neither want nor need regular employment, and only 4% of them joined the gig economy workforce to expand their skill set. Higher-income individuals with higher education levels are more aware of the gig economy compared to lower-income, less-educated subsets of the population, and slightly more than half of gig workers work on projects requiring a very specific skillset such as engineering and architecture.

The research also found 37% of gig workers receive at least 40% of their income from gig economy jobs, and 55% maintain regular, full-time jobs.

The survey included 10,044 US respondents, 65% of whom do not work in the gig economy and 35% who are now working in the gig economy or have worked in it in the past year.