The term "graphic novel sales" refers to the number of copies or units sold of graphic novels, which are a form of comics that tell a continuous story through words and pictures. Graphic novels can be in various genres such as fiction, non-fiction, biography, history, science fiction, fantasy, and more. The phrase "graphic novel sales" is often used by publishers, bookstores, and other industry professionals to track the popularity of graphic novels and make decisions about what titles to publish or stock on shelves.