This is more a matter of general cultural awareness, I would say. Gaiman's writing career goes back to _Don't Panic_, a book _about_ the Hitchhiker's Guide some 30 years ago now. He is a lot more than just a comics writer.
Anyway. I hope you try some of the books and enjoy them. I would say that he is perhaps more of a fabulist than a novelist -- a lot of his novels to me strike me as being akin to fairy tales, myths or legends, but with a fine modern sensibility.