There's tons of other resources out their that sound like a professional voice over. However they have no personality and don't sound like a individual talking

There's tons of other resources out their that sound like a professional voice over. However they have no personality and don't sound like a individual talking to you one to one. They sound like they are are polished for a mass audience with no personal attachment what so ever to the user. They sound like a robot repeating facts from a book. This is opposite to khan. Khan takes the 'brotherly'(Despite never knowing you) approach to teaching, and sometimes makes mistakes and lacks a little bit of polish. I think this is actually the key thing that makes khan academy work compared to other suppliers.