Daniel Ek — Spotify

Ek dropped out of KTH Royal Institute of Technology in Stockholm and by 23 was already a millionaire from his previous startup. He launched Spotify in 2008 when piracy was killing the music industry — and convinced labels that streaming could save them. Spotify now has 640 million users, pays over $9 billion per year to rights holders, and is worth $90+ billion. Ek essentially saved the music industry from itself while building a $6 billion personal fortune. Taylor Swift briefly removed her catalog in protest; she eventually came back. Everyone does.