In the Writer's Program catalogue of UCLA Extension, Judith Barksdale Inclan tells a wonderful (horrible) story of a book reading at which only ten people showed up, including a shy youth who sat at the back. She read from one of her books, answered a few questions--and sold no books. When everybody else had left, the boy approached her and asked whether she'd be willing to give him a book. She explained that she didn't have any of her own stock with her. He said, "Not one of your books. A book I really want."
Ouch. The lesson: if you're in this game, you'd better have a sense of humor.