As a self-published author, you are doing much more than writing. You're designing, marketing, managing, and driving the entire process from start to finish. You are bringing ideas to life, giving them tangible form.
When I first started writing, very few of my books were purchased or read. I wasn't sure if this was because I had a poor product or because no one knew about it. Perhaps it was a little of both, but over time I learned that there is no artificial line drawn between marketing and writing in the consumer's eyes. It's all the same thing.
In order to successfully launch a book, it's critical to recognize that EVERY activity is a marketing activity, from ideation and writing to design and publicity. Product, presentation, price and promotion are all essential elements of the book creation process. The best manuscript in the world will remain in obscurity without effective marketing and design. The worst manuscript in the world may sell a lot of copies initially, with the right marketing behind it, but sales will be hampered by product quality problems.
I used to write my manuscripts first and think about marketing second. More recently I've been doing the opposite -- I begin with a concept in mind, then think about the audience, cover art, back cover description, Amazon description and layout. After that I begin writing. This is the approach many experienced authors take when they pitch an idea to a traditional publisher.
Now I see my marketing efforts and my finished books as two sides of the same coin. Success requires putting the right product in front of the right people at the right time in order to make sales and get positive reviews, which will lead to more sales.