Martin Floreani loved being a college wrestler, but he wished he had had a winning record. If only, he thought, he had been able to better scout opponents and study up on his sport.

Light-bulb moment: In 2006, after graduating from college, Floreani and his track-star brother, Mark, bought a van on Craigslist and traveled the country, taping hundreds of local track and wrestling events, then put them on the Web. Traffic on their two sites, Flowrestling and Flotrack, took off as not just jocks but also proud moms and dads flocked to the sites. The brothers had tapped into an insatiable demand for school sports. "We didn't know how we were going to make money," says Martin. "But we knew we had a good product."

Today, their company, Flocasts, has 12 full-time staff members and countless volunteer videographers. It uploads hundreds of high school, college, and pro events each week from half a dozen sports. The company has posted 250,000 sports webcasts, watched by two million viewers a month. That has lured advertisers such as Puma and New Balance. The business also has a profitable sideline of paid subscriptions to training videos.