Review a chapter by reading summaries written by the page posse community.
Mark your progress in a book and never see summries from a chapter until you've read it.
After reading a section of a book. Review what others have said about it. Contribute by adding what you remember. Ask a question about the chapter and see what happens.
A posse picks a book to enjoy, but everyone reads at their own pace. See the other members' progress to avoid slipping secrets next time you talk to eachother.