In late 2004, Khan began tutoring his cousin in mathematics using Yahoo!'s Doodle notepad. When other relatives and friends sought his tutorial, he decided it would be more practical to distribute the tutorials on YouTube. Their popularity there and the testimonials of appreciative students prompted Khan to quit his job in finance in 2009 and focus on the Academy full-time.
Khan Academy's channel on YouTube http://www.youtube.com/user/khanacademy has 45+ million views so far and it's one of YouTube's most successful academic partners.
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