Connect students by textbooks

You are taking a class with a popular (or less than popular) textbook and the instructor is not that great. Or you need some extra guidance, but you are too shy to ask your classmates for help. Maybe you missed a few classes, but everyone is too busy studying for the test to get you up to speed.

What if there was a social network to connect current and past students of the same book for tutoring, study practice and collaboration? Learners could help each other as practice, altruistically, or find professional tutors with experience with the given textbook.