They had a good editor who saw the potential of the book when others couldn’t. She saw the author’s gift and made a masterpiece out of the book. And don’t discount the work of the copyeditors. This book was just about flawless, making it extremely easy to read. Book publishing is doing well these days because of such talented people, among other factors.
If you know a (or more) great editor(s) please, please send me their info. :).