Elance provides enterprises with online workers to do jobs such as programming from their homes. It is part of what Rosati and CrowdFlower CEO and Founder Lukas Biewald called a rapidly growing "human cloud" of skilled people who work online. They spoke on a panel discussion at the NetWork conference in San Francisco on Thursday.

Services like uTest, Amazon.com's Amazon Mechanical Turk, and LiveOps draw on this "human cloud" of skilled workers that can be employed on a flexible basis to carry out one-time tasks.

The U.S. Bureau of Labor Statistics (BLS) doesn't include these people its tally of U.S. workers, even though it does collect statistics on "temporary workers" from traditional employment agencies that supply labor within offices, Rosati said.

He thinks the BLS will examine the sector in 2011 and begin tracking it if "human cloud" employment makes up a large enough piece of the overall labor pie. Other economists and statisticians are likely to start paying attention to it as well, he believes.

While not tracked by BLS, the income of these workers is subject to taxes, and employers have to file tax paperwork to the Internal Revenue Service, Rosati said in an interview at NetWork after the presentation. Hiring human-cloud workers in foreign countries requires another set of steps to comply with federal regulations as well.