Rather than having a typical self-help (ie, You personally need to change NOW!) feel, the authors instead share interesting stories about how individuals accomplished goals of changing (mostly other people's) behavior. My favorite anecdote was in the section about changing "the path". A high school teacher had two students who disrupted the class by coming in late every day. He knew he couldn't appeal to the thinking part of their brains (they already knew they were coming in late) or the emotional part of their brains (they didn't care they were coming in late). Instead he bought an old couch and put it front and center in the classroom. The couch quickly became the cool place to sit and the two students started to come early so they could get a spot on the couch, right in front of the teacher, where he could also keep a better eye on their behavior.
The authors actually put a lot of emphasis on changing the environment when you want to change behavior (yours or others). One quote (and I'm paraphrasing because I don't feel like looking it up right now) they use over and over again is, "What often looks like a people problem is really an environment problem."
Most of the book had to do with changing other people's behavior, but there was one exercise in "the rider" section that I thought was interesting and could apply to changing personal behavior as well. It's called The Miracle exercise. In it, you imagine you go to sleep at night and a miracle occurs that solves your problem. When you wake up in the morning, how do you know it's solved? You can take that list of things and turn them into specific behaviors to change. Taking an example from the book, if you have a problem fighting with your spouse, you might imagine that if a miracle occurred overnight, when you woke up, you'd be kinder, more helpful, more affectionate, etc. And those are exactly the things you should do if you want to have a better relationship with your spouse. The science of the blindingly obvious? Maybe. But I actually thought it was an interesting exercise.
I think this book would appeal to anyone who likes this sort of thing. It's a quick read and has good anecdotes. It's (obviously) not going to solve all your problems, but it did have a hefty chunk of interesting things to think about.