I should probably mention up front that I read this book while I was waiting for something, not because I was interested in the subject. Overall, it was a decent book and held my attention from cover to cover. However, I am pretty sure that if you take this book's advice, you will either become a doormat or everyone will think you've taken a vow of silence.
The idea is to take the challenge to stop complaining out loud for 21 days (at which point it will supposedly become a habit) but almost half of the book is actually about "The Secret" which is the very old idea that you can make good things happen to you by thinking about them. I understand why the author included that, even though it's not his own idea. If you're using your intentions to make good things happen to you, then you will have less to complain about.
My favorite part of the book was when he explained why people complain and what you can do about it. For example, people complain because they want attention, remove responsibility from themselves, inspire envy, have power (point out flaws in others just to say they don't have that flaw), and excuse their poor performance. So if you determine that they just want to remove the responsibility for their problem by playing the "yes, but" game, you can say, "I have faith in your ability to handle your problem" and if you say it often enough, they will either solve their problem or stop talking to you. Either way, you win. This advice was the best and made it all worth the read.
My least favorite part was all the filler. I think there are way too many testimonials: at least one to start every chapter and then a chapter full of them at the end. He also includes some seriously disturbing, graphic stories of people who remained positive when they had bad things happen to them. Without all the filler of testimonials, stories about how awful it is to hear people complain, and all the stuff about The Secret, the book would be more of a pamphlet.
I'm not sure if I will actually try and stop complaining, but I kind of like the idea. Now I am unsure how I can point out things that are negative without it being complaining. He says that it's OK to point out problems as long as it's to the person who is directly responsible and if you have the right tone of voice. I don't know if I can handle that but even if I'm not sure when I am complaining or stating a fact, I think it will benefit me to be mindful of when I am possibly complaining or being negative.