It's an interesting book, even if you don't believe in auras. It's really a book to help you understand your personality.
As an author, I enjoy books like that. Not just for their insight into me, but also for insight into my characters.
Yes, I know I can make my characters do whatever I want them to. But even in the realm of paranormal fiction, I believe the character has to be "realistic." A werewolf must be part human, part wolf. An invisible man must deal with the issue of clothing. At some point a ghost must realize he or she is dead.
Characters must fit the story. If the character isn't believable, the story won't hold up. Therefore, I like those personality quizzes so I have a great idea of how my characters would act in a given situation. (I also look up their Sun and Moon signs for an astrological look into their personalities.)
If you can't tell, I enjoy the character driven stories. In my mind, nothing is as interesting as people and why they do whatever they do. Finding out what color their aura is, what their moon sign is, and even which Michael Jackson dance step they are most like is important to me.
So, what are your favorite personality quizzes? I'd love to know!