I picked up this book shortly after Little Boy turned a year old and officially became a toddler. It turned out that the bratty behavior he was exhibiting back then was just a manifestation of over-tiredness, but now at 18 months I decided to revisit the book, and wouldn't you know? The advice is working!
Harvey Karp spends about half the book on positive-reinforement behaviors, most of which we were already doing. His advice to curb negative behaviors is based on two key points: the Fast Food Rule, which is repeating back the toddler's wishes so they feel like they're are being listened to, and Toddlerease, essentially talking in simple phrases. Ever since I started using this method, Little Boy stops crying within seconds and definitely less than a minute, then I can diffuse the situation and we can be on our way! Needless to say, even though it is slightly more wordy than necessary, I highly recommend the book!