Estimates say there are over 3,000,000 registered freelancers worldwide, competing for everything from computer programming and web design to finance and engineering.

How can you make yourself more attractive to potential employers?  

You have to look diverse enough to be able to handle different things, and experienced enough to handle what employers want.  

"Previous findings would suggest that freelancers should specialize in a particular type of work so prospective employers know what they're good at," says  Ming D. Leung, assistant professor, UC Berkeley's Haas School of Business, "But I was curious about how freelancers can demonstrate their skills and commitment in an online world to acquire more jobs. My research suggests that employers on Elance.com appear to value freelancers who demonstrate their commitment by making incremental moves between jobs."

Direct competition with other freelancers searching for online work presents new challenges. And in the virtual workplace. Employers are often concerned with how engaged and committed a virtual, non-local worker will be, regardless of a freelancer's job history and ratings/feedback from prior employers. 

To understand how employers navigate the uncertainty of not meeting a potential hire in person, Leung analyzed millions of job applications and more than 100,000 worker profiles around the world from a 2007 data set provided by Elance.com, a job site for freelancers where he is an advisor. Leung began by calculating how similar jobs on Elance were to one another. He then looked at the jobs each freelancer completed and found that those who exhibited some movement in their past history — by taking jobs that were similar to one another but not the same — were more likely to get hired through the website than those freelancers who accumulated experiences from dissimilar jobs or from jobs that were identical.

Leung says the rise in contract and temporary employment is leading employers to increasingly embrace such a virtual workforce for specific skills and flexible employment arrangements. He also notes that in contrast to past characterizations of contract employees being low skilled and low paid, today's freelancers are also performing highly skilled tasks.

By better understanding the market's dynamics, freelancers will be more prepared to demonstrate their credibility and competence to employers.