If you have any hope of having your book achieve financial and critical success, you must realize how your readers (your customers), view your book (your product) when they first see it (online or on a shelf). Once you fully recognize how your readers will perceive your book when they first see it, then you can adjust your book accordingly.
Other advantages of marketing can be that exactly the book is not the only thing that end up being sold. Autographed pictures, or autographed book covers co