Catherine Cook started what became a multimillion-dollar company when she was just 15 years old.
Cook came up with the idea when she moved to a new high school. Feeling a little lonely, she tried to come up with a way to meet new friends.
That's when she came up with her million-dollar concept: create your own high school yearbook page to meet new people who share your interests, then post it online.
So myyearbook.com was born and after just nine months, more than a million people were using it.
"The first million was definitely the most shocking, the most like, 'This is big!' " Cook says.
And it just kept growing. More than 30 million people are now logging on to Cook's website.
Cook is now 21 and she just sold the company for $100 million!
She has just been named Entrepreneur of the Year by Ernst & Young. When we dropped by her office in New Jersey, she was talking corporate strategy with her brother Geoff.
She has advice for young people worried about the scary job market.
"I was 15, in high school, living in my mom's house, and basically my alternative job would be bagging groceries at the supermarket. So, why not do something cooler?" she said.
The siblings say they expect to be starting more companies in the future.