Company: Statcounter

Net worth: $28 Million (est.)

This tech-savvy Irishman founded his web analytics company at the age of 16. Since 2008, Statcounter has accounted for over 2 million users and 15 billion page views across its three-million-website network. Throw ad revenue into the equation and you have a multi-billion-dollar business run by a multimillionaire.