While search engines are not the only area that authors and publishers need to focus on to promote their books and their brand, there are some key factors that need to be focused on to drive the highest ranking possible in Search Engine Results Pages (SERPs).
Great set of articles by Children's author Karen Ingles demonstrating what an author should know about their audience, how they buy and how to engage them.
Amazon's Primevideo is example of new approaches to book discovery and distribution being used by publishers and retailers. This is an area of ongoing research and product development for Outcome Labs.