Justin.tv was its name before, and it started with just one guy (Justin) broadcasting his life 24/7. This was a time when the term “live streaming” was not popular—even they at Justin.tv called it “lifecast”. The channel was run by Justin and three of his friends, Michael Seibel, Emmett Shear, and Kyle Vogt. And it was them who suggested the idea to him, thinking that his party antics, humor, and personality just needed to be shared with other people.
Source: http://new.blicio.us/how-twitch-got-started-what-happened-to-justin-tv/