A successful event is not measured by the amount of books sold (and I don't just say that so you can say, "of course, you'd say that"). Did I learn something? Did I meet new people? Was I pointed in the direction of someone/something that could help me? Did I meet young people who want to know about my subject or about how to publish a subject in which they're interested? Whether it was humbling or electrifying, it must be eye-opening. This is about swag, people; swerve. If you don't know, now you know. I'm selling myself, not books. The books will come, errr, go...oh, you know what I mean!