This question is primarily directed at Kris, though if anyone has any insight to offer, please post away.
I've attended a couple of gaming, anime and comic book conventions in my time. Once I was even an exhibitor. I pooled together some funds and set up a small booth at a local gaming con, hoping to promote and sell my company's table top RPG. By the end of the weekend we hadn't sold a single copy. In retrospect the organizers really didn't seem that interested in supporting the exhibitors. They didn't clearly mark the location of the dealers' room, didn't print up a list of dealers, offer much in the way of ads, etc. Or perhaps I just wasn't good at drawing in customers. I wasn't the only frustrated dealer, that much I know.
I've also heard quite a few horror stories from both the perspective of dealers and attendees (the infamous Dashcon, for example). So it seems a lot of planning, skill, and organization needs to go into a successful convention. There are also probably some tricks to being a successful dealer. As a convention veteran, what advice would you offer to people who want to organize a convention, those who want to be a dealer at a con and (to a lesser extent) people who simply attend them? The dos, the don'ts, etc.
If there isn't already a book or e-book on this subject, someone ought to write it.