Writing books is a lot of work. You put a lot of time and effort into it.
You would surely hate it if nobody ever bought your book. Writing a book is hard enough; you don’t need the frustration and the feeling you wasted your time added on.
I have news for you; some people make the mistake of posting the image and title of their book on social media but not making it possible to actually find the book and buy it. It irritates me to click on the book image then not being able to find the book and preview it before perhaps buying it.
You may only get one chance to leave a lasting impression with each potential reader. Every time you post the title, image and description of your book, be sure to hyperlink the purchase link for your book into the promotion page.
Finally, promote your books through social media, Facebook writers groups, book promotion websites, your own author website and more. Not promoting your books makes it too hard for people to find them.