If I were to use a pen name, I think it would be... Nathan Dangerfire. For interviews I'd wear a scarf, and a cape, and also thigh-high leather boots like those musketeers in movies have. On a little more serious note, can the name of the author make a difference to whether a book does well or not? George Orwell, Lewis Carroll, Joseph Conrad, Josephine Tey, Mark Twain and many others used pen names... I imagine it was to be more marketable.