Does this mean, with the 2 books/month plan, a subscriber can 2 books only a month, or he can keep two books at a time like the way Netflix does for movies? ALthough reading two books a month is an ardent task, but for some fast readers they can read more. If 2 books/month is a hard limit, what happens if I read 1 book a month? Do I get an extra book the following month?