Where Khan Academy has the distinct advantage to me is not in its content or teaching style (both of which seem good) but in the ability for the student who does not grasp the subject to be able to replay the lesson over and over without fear of holding up the class or causing the teacher inconvenience thereby allowing the students who do understand the ability to move on to the next subject without having to "read ahead". The overall content covered can be greater overall in a shorter amount of time.

Kids don't want to seem different from other kids. If a child has to ask the teacher to repeat the lesson or stay after for extra help he may be perceived by his peers (or feel as though he is being seen as) as slower or stupid. With KA on the other hand the student can learn at his own pace...something that just cannot be done in a class of 30+.

Khan Academy does not get upset if a student does a search and finds another method to solve the problem at hand (I don't know how many times I was told "I don't care if you are getting the right answer, we want you to do it our way" when I was in school).

To me it is not about KA at all...but more about self education. The best teacher is you, the lecturer may be giving you the information but how you perceive and use it is entirely based on you. It is a simple fact that teachers cannot at the same time be paid more and have smaller class sizes...the funding is not there. Students are going to fall behind unless they are taught early on to not rely entirely on the teacher to show them "everything". We have at our disposal the most powerful learning tool in the history of man...The internet. No longer are libraries bound to the confines of a building down the road that you may or may not have access to. This is the most amazing thing to me, decentralization of learning, and those who profit from learning in the old system obviously are going to be worried about their future income.