Don’t worry, I’m not going to recommend you change your heart-wrenching, tearjerker ending to something softer and sweeter just to make your reader happy. Some of the most satisfying books I’ve read have required a whole box of Kleenex.
By “reader focused” I mean thinking heavily about the reader’s experience as he or she reads your story. Are sentences smooth and easy to understand? Are transitions between scenes or chapters logical? Is the story cohesive, progressing logically from start to finish? Do any twists and turns make sense in the end?
The more satisfied a reader is by the book, the more likely she’ll be to pick up the next thing you write. A satisfied reader comes back—and she brings her friends with her.