How to Write a Great Science Fiction Book

In the book, I tell what is the main genre and then what are the most popular subgenres of that form. In Amazon, because they're basing it on the marketing of these books, they want to break down the subgenres into as fine a distinction as possible. The real trick in terms of writing the story is to know what your main genre is and what the main sub genre might be. Then when it comes to marketing it, that's knowing what that book is going to work best on on Amazon.