[gostsamo]

This is a book club. People know each other and their preferences. Also, it would be rather clear if people liked the book or not. Those are functions better left to the conversation or at least, no sense in making them anonymous.

For online discussions, it might be convenient to have a shared board with questions about the book, maybe scoreboard to rate by aspects and do a final grate, but those are fancies, not essential for facilitating the discussion.