[eltonlin]

Maybe you're right, but I'd challenge your middle paragraph.

When there are 10 students, they often have some common misundersetandings that can be addressed together e.g. they all want a review of Taylor's theorem needed to do electromagnetism, and they forgot it from high school. So I argue there is a lot of room for reusability of explanations.

>"pay $10 to watch another guy get tutoring" The format async., so if person A asks a question, person B doesn't have to sit and watch. The same way it works on Stackoverflow - if someone asks a useful question that you wanted to ask, you can reap the rewards of the existing answer.