Most of his readers were women. Asked why this was the case he said: "I like to write about women who are talented and capable, but most important, retain their femininity. Women have tremendous power — their femininity, because men can't do without it." Books were Sheldon's favorite medium. "I love writing books," he commented. "Movies are a collaborative medium, and everyone is second-guessing you. When you do a novel you're on your own. It's a freedom that doesn't exist in any other medium." He was the author of 18 novels which have sold over 300 million copies.