You could also say this group of books contain events. Much is said about the particular event as we know of it before publishing, but as for the author's life, that is often the more interesting parts of the book. You would call these events, the unknowns! Sometimes as author may include an event in their book that they would not have said to a select group of people. Obviously, the more events that are interesting, humorous, shocking, and of course, not already known, really does increase book sales!
You can now enjoy your favorite life story of an author in at least two formats including audio book!