TEENAGE DREAM: Teenagers no longer need to mow lawns or babysit, today's youth are starting businesses of their own, and making millions doing it.

• Author: Penrod, Emma

Aspiring engineer Spencer Harrison was just 13 years old and sitting around the campfire with his brother and cousins when he conceived an idea for an improved campfire roasting stick. "We were scouters, and every single campout we ate marshmallows and nothing else," he says. "I wanted variety."

His father, a former small business owner himself, encouraged Mr. Harrison to try selling the campfire sticks instead of getting a summer job. Mr. Harrison was skeptical at first, but started knocking on doors and traveling to local fairs to make his sales pitch. Five years later, Mr. Harrison's Wolf 'Em Sticks are available in 250 stores and bringing in about a quarter million dollars in sales annually.

"The more you're into it, the longer you go, the more you realize that this is possible," says Mr. Harrison, now 18 and headed to his first year of college. "Sometimes you don't need that fast food job. You can work on your future right now."

Youth have long exhibited entrepreneurial instincts, scraping together spending money with just about any marketable skill or product they can come by--mowing lawns, babysitting, selling lemonade. Mr. Harrison and his peers have aimed a little higher, riding a recent wave of interest in young entrepreneurs to launch business ventures that have them hiring employees before they graduate high school.

While programs intended to help teens write and pitch business plans have inspired hundreds of youth, only a handful of their participants turn their early business ventures into careers. What young entrepreneurs really need to stay in business, the successful teens say, is more real-world experience. They need to be allowed to struggle and fail, they need access to real-life resources, and they need mentors who view them as legitimate business leaders despite their inexperience.

ENTREPRENEURSHIP IS THE NEW SUMMER JOB

Rex Falkenrath founded his first tire distribution company at age 11, after watching a truck deliver tires to the gas station at the end of his street. He retired in 2008 after managing his auto parts distribution company, Number 1 International, for over 35 years. Midway through his career, he branched out and started Techniphase Industries, which developed and manufactured more fuel-efficient parts for internal engines. But it all started, he said, with a kid who would measure his neighbors' tire tread and ask stay-at-home housewives if they would like him to deliver new, safer tires before someone in the family had an accident.

"I was a really strong personality as a kid," Mr. Falkenrath says. "My moto was, 'patience--forget that.' I just wanted to make something happen."

It's hard to get data on how many kids who start tire delivery services go on to run...