I guess that it's like any other business. I am a photographer and a short story writer. I approach selling my writing in the same way I sell my photography. Books are a product like any other, and the more competitive the market gets, the more the author has to do. Some authors seem to churn out several books a year, and have a massive social media following. Whether it comes down to how much money they put behind it, or energy, is hard to say. I would suggest that if you are a writer and hate the whole marketing process and social media, maybe pick two platforms you prefer and stick to those. It's better to do well at one or two than spread yourself thin, and all your time working to promote. Great article, so thank you!