Self-help books

Although I've never read a self-help book, I know that people read them to better themselves. but what do I think of them? They could be cheesy traps for people who need help in that area to get sucked into without really getting help. Or, they may actually help people change and stay the way they want to be. In my opinion, they can be both.
I once listened to a radio show where some important person (important because he wrote the book) wrote a book on "How to Change your Kids in 5 Days." No, not like their personalities, but their bad bratty attitudes and their spoiled ways, and certain ways parents should act to prevent that. It seemed like it actually works. So I imagine other books must help and work as well. However, there most likely are books out there that tell you that you should change, but they don't say how. i.e.-weight loss books, they probably make you feel self-conscious and tell you to excercise and eat right, but they don't tell you the steps you should take to proceed.
So, to sum it up, I think that Self-help books can go either way. Half the books out there are possibly like that change your kid book and definitely help you out, but the other half are completely pointless and just make you feel inferior.