A published book is like having a pet. It might survive without your full attention, but will it thrive? Anyone who has invited a cat, dog or other pet into their home has learned that the animal responds more easily and more positively when you spend time with it. And, when you’re involved with your pet, you enjoy it more, too. There are benefits for both the animal and you when you pay attention to it, care for it at a physical and emotional level, understand more about what it needs and wants and take care of those requirements and desires.
How does a published book differ? While it is not a living breathing life form, as the author, you may feel an emotional attachment to the book you have created. And you will get out of authorship whatever you are willing to put into it.
If you spread the word about your book, it will sell. If a high sales record is your goal, you will meet with success only if you do the work—put in the time and energy. As with a pet, you will get out of the relationship (or experience) whatever you are willing to put into it. The benefits or rewards will be in direct alignment with your efforts.