If you decided to experiment with the next wave of publishing, and have published your treasured novel / non-fiction book as an eBook, perhaps on Amazon's Kindle Ebooks, then your marketing will depend solely on you.
But things are not as bad as this might make them seem.
For starters, your book will only compete with 1 million eBooks, not 14 million.
And it will be available for purchase for decades to come, unlikely printed books which sink or swim in less than a year or so.
And you also can get some helpful hints from your fellow Kindle eBook writers.
Kindle has set up a forum to help authors, which you can see here.
There you can get in touch with the Kindle Direct Publishing (KDP) Community. Many authors and publishers are members of this Community, with their own titles for sale in Amazon's Kindle Store. The Help pages of this site offer tips for publishing your Kindle eBook.
Kindle also set up another forum called the Voice of the Author / Publisher. You can check this forum here.
As Kindle's welcome post on this forum puts it:
This section is all about you, the KDP authors. What have you learned publishing on KDP? What’s your experience in marketing your books? What would you like to share with new authors on KDP? This is where you can share your experience with all things KDP, together with marketing secrets. It’s really a place for your voice and your points of interest. So, make yourself at home and get the forum going.