As we process applications for the 2010 Inc. 500 | 5000, we thought it would be worthwhile to shine a spotlight on some of the companies that are vying to appear on our ranking of the fastest-growing private companies in the U.S. One that caught our eye was Los Angeles-based RockCorps.

Tickets to concerts of popular recording artists like Akon and Kanye West can cost hundreds of dollars, but Los Angeles-based production company RockCorps cashes in with a different kind of currency: four hours of your time spent volunteering.

"We knew that volunteering and giving back was becoming a real passion point for young people," says COO and co-founder Grady Lee. "We developed a brand platform that connected our brand partners to the power of young people."

Lee and a group of six other friends founded the company in 2005, which currently partners with French telecommunications company Orange, and previously with Boost Mobile, to produce and promote concerts in the United States, the United Kingdom, France, and Israel. So far, they've recruited 60,000 volunteers.

RockCorps reaches out to a list of almost 600 charities and non-profit organizations such as the Red Cross, the Boy's and Girl's Club, and local organizations. They then organize and promote 40 to 50 volunteer events in association with a live show only for the thousands of volunteers who give four hours of their time to earn a ticket. More than one-third of volunteers end up coming back to volunteer, without the incentive of a concert ticket, Lee says.

"We design the projects so they're fun, but they're also transformative in nature," he says. "We're exercising the muscle that young people have power in the world and something to give back."

The company's revenue last year surged 48 percent over the previous three years to almost $10 million. "To connect with young people that way is a unique proposition, and brands are really finding the value in that," Lee says.