Buying a book does much more for an author who isn't already famous than just giving them money does. It raises their visibility, making it more likely that pub

Buying a book does much more for an author who isn't already famous than just giving them money does. It raises their visibility, making it more likely that publishers will bite on a second book by them. It also pays the editors, typesetters, etc. - the author isn't the only creative person involved, and every heavy reader can think of examples of authors who have good ideas but desperately need an editor.