In addition to his books about ghosts, Mars, Oliver Cromwell's embalmed head, weird things on eBay, sideshow performers, and unorthodox messages from God, Hartzman has written for Mental Floss, the Huffington Post, AOL Weird News, AllThatsInteresting.com, The Morbid Anatomy Online Journal, and Bizarre magazine. He's discussed oddities on CNN, MSNBC, Ripley’s Radio, and the Travel Channel's Mysteries at the Museum.
More of his love for the unusual can be found on his site, WeirdHistorian.com. Outside of these projects, Hartzman earns a living as an award-winning advertising creative director.