 The Halo adaptations have been successful as well . Many of the novels have appeared on Publisher Weekly 's bestseller charts and the Halo Graphic Novel sold more than 100 @,@ 000 copies , a " rare hit " for the games @-@ to @-@ comics genre . Ghosts of Onyx , Contact Harvest , The Cole Protocol and the first volume of Cryptum appeared on The New York Times bestseller lists , and The Cole Protocol also opened 50th overall on USA Today 's bestsellers list . Tor 's first three novels sold more than one million copies by April 2009 . 
