These entrepreneurs, interviewed by Forbes over the last three years, started launching businesses by the tender age of 9. Some of them identified problems and created companies to solve them, while others turned their hobbies into money-making ventures. Some teamed up with friends, parents and mentors; others plowed ahead on their own. To qualify for this round-up, the kids had to have cracked $1 million in revenue before college graduation and by age 22 (or be on track to do so), or had to have received funding that valued their operations at $1 million or more.

Autocricket
In the summer of 2008, after his high school graduation, Jason Brian started working in the marketing department of a South Florida car dealership. He knew the future of marketing was on the Web. "With half of the money, I found that I could double the results," by buying online ads and using search engine optimization techniques, he recalls. Three years later, at age 21, Brian spent "less than $10,000" of his savings to build a website that would help consumers look for cars. Autocricket.com made money by selling customers' information to dealers and manufacturers, which could market to customers directly. Six months after launch the site attracted the attention of two entrepreneurs in Naples, Fla., who invested $250,000. The site generated $1.2 million in revenue in 2009, when Brian was 22. In 2010 it did $6 million.


Showclix
In 2005, when he was 18, Joshua Dziabiak sold his first company--a Web hosting firm called Mediacatch--for north of $1 million. He bought a Mercedes (in cash) and a flat-screen TV, and used the rest to invest in other companies, including Showclix, his current venture, a website that lets performing arts centers, colleges, live music venues and other outlets sell tickets online, over the phone and at their box offices. In 2009 he raised nearly $1 million, which valued the company at $2.75 million. Showclix collects services fees (usually paid by the ticket buyer) of 7% to 15% of ticket sales. Those fees brought in $9 million last year.




Metrolyrics.com
In 2002, when Milun Tesovic was 16, he started a music website as a hobby, compiling lyrics to his favorite songs. Two years later he decided to turn it into a company. Today Metrolyrics.com has a database of lyrics of 2 million songs; it licenses some of them, and others users post on the site for free. The company, now with 20 employees, makes money selling ads, and hit $1 million in revenue in 2007, when Tesovic was 21. Tesovic juggles work with classes at Simon Fraser University in British Columbia, Canada, where he is a business major. "For me education isn't helping me find a career," he says. "It's more about growing myself."

Solben
Twenty-year-old Daniel Gómez Iñiguez launched Solben, a company that designs and manufactures a press that extracts oil from plants to produce diesel fuel. Iñiguez began his R&D in high school. He sold to his first client for $150,000--$75,000 up front to help build the product, followed by $75,000 upon delivery. The Monterrey, Mexico, company brought in "a little over $1 million" in revenue during its first year of business. Today it employs 15 full-time staff; Iñiguez is entering his junior year of college.






Glasses Direct
When 21-year-old university student Jamie Murray Wells attempted to buy a pair of prescription eyeglasses in 2004, he had a vision for a new type of business. Nonplussed by the $300 price tag, Wells decided to leave school and funnel his $2,000 student loan into what would become Glasses Direct, a London-based online retailer. In the first year the company's revenue topped $2 million.
Note: At the time of this writing, in 2010, the company pulled in $5 million in annual revenue, employed 70 people and had raked in $34 million in venture funding.

Dave Hogan/Getty

SuperJam
In 2002, at the age of 14, Fraser Doherty started making jams in his parents' kitchen in Edinburgh, Scotland. By age 16 Doherty left school to work on his jams full time. SuperJam's revenue hit $1.2 million in 2009.
Note: At the time of this writing, in 2010, Doherty remained the company's only full-time employee. Based on a reasonable valuation multiple of one time revenue (jelly maker J.M. Smucker traded between 1 and 1.5 times revenue), Doherty's debt-free stake was worth between $1 million and $2 million.


Mydesktop.com
In 1996 Michael Furdyk, then 16, started MyDesktop.com, an online computer magazine, in the basement of his parents' home in suburban Toronto. His site was filled with tips and advice Furdyk gleaned in online chat rooms, where he came across fellow teenager Michael Hayman. Hayman, an Australian, moved to Toronto to help build the business. Running lean, the pair bartered for website storage space and office rent. Soon MyDesktop.com was bringing in $60,000 a month in ad revenue from blue-chip clients like Microsoft.
Note: In 1999 Furdyk, Hayman and a third partner sold the site to Internet.com for "over $1 million," Furdyk told Forbes in 2010.
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