Hi Ron. Thank you for commenting. By the 90/10 comment, it means that a writer might spend a full year writing the book, and then spend the next 9 years marketing the book. In other words, marketing a book never ends.
Joseph C. Kunz, Jr. wrote a new post, Getting A Big Name To Write Your Book’s Foreword: An Introduction For Self-Publishers, on the site Self-Publishing Review 1 year ago