Source

Here's how it does it

A good book would be passed on by word of mouth when readers read it. This is because book lovers would want to share the goodness. Those in book clubs would recommend it and nominate it for reading and discussion. From there, the name of the b0ok would be out there and fan bases may crop up; creating a solid community to get the book to a lot more people.

A well known author's books would sell on the merit of past publications.most people buy books of authors they are already familiar with. The authors of past bestsellers are an example, their already made name would push customers to buy their new book because they want more of the same. I ,for one, never bypass a Nora Roberts book when I am book buying.

A book may sell itself if its topic is trending at the time. It doesn't need to be good. A book, not necessarily a good one, may sell itself if its topic is trending at the time.

A book may sell itself if the author gets entangled in some kind of scandal. Two things may happen, one book sales may plummet or they may soar. Some of the customers may purchase that author's book as worth reading especially if that author said something against their favourite author. The scandal between Chimamanda Ngozi Adichie and Akwaeke Emezi led me to check out the latter’s work. with some prejudice and resentment nonetheless. I guess you could say those feelings coloured my review.