iBooks Author

So, if I am a professor (or maybe a teacher in some situations) and I can assign my own textbook as a required reading, could I make more money if I have the students purchase a self-published version? Apple gets 30% and I get 70%. The publisher gets 0%, they've been cut out. The students also can't resell it.

But, I can't sell my book anywhere else? What about the students who don't have an iPad?