8. Spotify: Daniel Ek
Sweedish entrepreneur Daniel Ek, who reportedly founded his first company when he was 14 years old, is perhaps best-known for starting up music streaming service Spotify in 2008. Prior to Spotify, Ek enrolled at the Royal Institute of Technology but did not complete his degree. His other ventures include founding Advertigo, an ad company acquired by TradeDoubler, as well as positions as CTO at Jajja Communications and Stardoll.
Twenty-nine-year-old Ek is reportedly worth $306 million.