The Secret is based on the concept known as "The Laws of Attraction". In short, you are ultimately responsible for what happens to you. It's not just issues where you start taking drugs and you become a suicidal junkie. If you don't have the job you want, it's your fault. If you don't have enough money, it's your fault. If you get hit by a car while sitting in your living room, it's your fault. Why? You have been sending out mystical "orders"to the universe, and you don't even know it. The universe is merely acting as your personal genie granting you your every "wish" (and you aren't even limited to just three). With The Secret you can harness this power to get the things you really want.
What's the problem with getting what you want? Probably nothing. Unfortunately, The Secret can't deliver. It amounts to little more than New Age mumbo jumbo that promises great things with nothing to it. I won't argue that having a positive outlook and being generally optimistic will make life better for you. With those traits you are more likely to be around other people who are positive and more willing to support you. You are also more likely to try more things and take advantages of opportunities that present themselves. The Secret makes bigger claims than this and that's where it fails. Your thoughts don't send out orders to the universe, they only affect how you act in life. I can think about having $1M and it will not fall into my lap. I need to find a way to earn that $1M. This example may seem silly, but there are examples on the official website like this one. You can find the story table of contents here.
The most common complaint I have heard about The Secret is how it blames the victim. As I stated above, the bad things that happen to you are based on the orders you send out to the universe. I wish I had the book in front of me so I could cite the page. In one part of the book, the author basically blames the holocaust on the Jews. It's not state plainly as in the previous sentence, but the description seemed rather clear to me in the book. Again, I don't have the quote in front of me, but the book states in essence 'even the most horrible atrocities are caused by the thought of those affected'. There are instances, many I suspect, where we bring bad things upon ourselves. Many are likely inadvertent, but we can learn from these experiences and do better in the future. It's not that revolutionary.
My biggest complaint is really about how the book is a rip-off. First it gives the reader cheap New Age advice that offers little real benefit. Second it's way over-priced for what you get. The hard-cover book runs around $25 for a 198 page book. That doesn't sound so bad at first. Realize the font for the book is large and the pages small. If the book were condensed to normal font size and printed on pages typical to most hard-cover books, The Secret would likely run 75-90 pages (my guess). That should cut the price to $15 at the most. On top of that, the book is more repetitive than Groundhog Day. If the repetition were removed, the book would be reduced to roughly 10 pages for a normal hard-cover formatted book. That's a pamphlet that should only cost $2. Ultimately, The Secret is really like those novelty books they have in the little spinners located randomly around your local book store. The advice is about as good and the format is perfect. I can't wait until the 'condensed' version of The Secret comes out.