Almost a quarter of all workers in the United States fulfill some type of freelance work. That’s according to the Staples Advantage Workplace Index, a study by the B2B division of Staples that looked at trends among American office workers. The study found that 12% of employees freelance for their primary income, while another 12% freelance in addition to holding a primary job.

“For businesses, augmenting staff with temporary, contract workers is not new,” said Neil Ringel, executive vice president of Staples Advantage. “While the organized online marketplace makes it easier to tap into a pool of skilled workers, businesses need to pay attention to the needs and expectations of freelancers and independent contractors as they can be quite different.”

Among the reasons cited for freelancing were the flexibility to make personal  hours (37%), the opportunity to make more money (39%) and the ability to balance work and personal life more effectively (32%). Businesses can also benefit by tapping into a pool of potential temporary workers who have very specific skill sets needed for special projects.

“The freelance economy is a win-win for people who have a desire to work on their own time and companies who want to streamline in-house operations,” said Pat Griffin, enterprise account executive at HourlyNerd, which links up businesses with temporary employees with specific expertise. “With smart, collaborative technology becoming more mainstream, the freelance economy enables businesses to redefine their workplace strategy, making the physical workspace more effective by establishing efficient team structures and collaboration models.”

In another employment report, the Labor Department reported this week in its monthly Job Openings and Labor Turnover Survey that the number of Americans who voluntarily quit their jobs in November climbed to the highest level since April 2008, to 2.8 million workers. This signals a rise in employee confidence in the job market and points to a strengthening economy, in which workers are more likely to voluntarily leave their jobs for other openings or perhaps to freelance on their own. In a weaker economy, employees are more likely to be laid off.

While the economy has yet to return to pre-2008 recession levels, the numbers look promising. In the throes of the recession, there was just one job posted for every seven unemployed people. As of this past November, there was one job for every 1.5 unemployed workers.