This works well for regular books as well as eBooks
A search engine crawler will read the code. After a period of time, the search engine results page for users performing a “branded search” will yield the below information (see photo). It is important that this information generally presents only for users who are performing the search within your geographical area.
After months of waiting, Google decided to give me a nice formatted “Book” knowledge panel at the top of the SERPs. SEO at its finest.
Note, the only markup that I used was the book JSON-LD shown above.