You can read the full Movie Marketing Madness column for Harry Potter and the Prisoner of Azkaban at Film Threat:

Unlike with The Lord of the Rings, there was no continuation of the story in 2003. Have you ever been talking with someone, had a really good conversation going, and then one of you gets up to go to the bathroom? The conversation is never quite as good after that brief interruption. 2003 could prove to the bathroom break for the Harry Potter film franchise. Interesting, since J.K. Rowling seems to be able to take her sweet time with the books with no adverse reaction.