"I quit my career to do this," Khan said. "I think this is a huge social return on investment. The cost of producing these videos and having it up there is lower than supporting a small rural one house schoolhouse. It's a ridiculously small cost where you can educate the world."
Nebraska teen Lucas Cruikshank, who began portraying fictional character Fred Figglehorn -- a 6-year-old with a high-pitched voice -- is said to be making $1 million on ads on his popular YouTube channel. (His YouTube channel was one of the first to cross the one-million-subscriber mark.)
There's also something priceless YouTube has done. Consider the video "Dramatic Chipmunk 6." It's only six seconds long but more than 20 million people have watched it. Why? It's a viral phenomenon.
The same holds for the keyboard cat, the infectious refrain "Charlie Bit Me," or Susan Boyle, whose YouTube audience was vastly larger than the British TV audience that discovered her. That's big and, to think, it's only been five years. That's some short history of making history.