In Amazon.com rankings for tie-in books, Cormac McCarthy‘s recently adapted novel, “The Road” and a tie-in book for James Cameron‘s Avatar currently lead the field.

Produced by HarperCollins’ It Books imprint, the new book, “Avatar: A Confidential Report on the Biological and Social History of Pandora,” is meant to supplement the film–an original screenplay written by the director.

It was a blockbuster weekend for Avatar. During its opening weekend and a massive east coast storm, the film still earned about $73 million, according to Box Office Mojo estimates. That was the highest grossing opening weekend ever for a film that wasn’t directly adapted from a book or comic book.

Interestingly enough, seven of the ten films on the highest grossing opening weekend list originated as books or comic books. The blockbuster list includes: Shrek sequels, two Spider-Man films, The Dark Knight, and The Twilight Saga: New Moon. Editor’s Note: An earlier version of this post miscounted the blockbuster list.