The Audience Makes a Book

It's true that authors write their books, but it's the audience who "makes" a book.

In other words, a lot of the power of a book comes from the fact that it has been recommended by a lot of people. A book is by default just the point of view of one person. It means something different if it corresponds with the desires, judgments, or experiences of lots of people -- they have affirmed its truth from their perspectives.