"Hooked" presents a simple, yet very useful model to channel your thoughts when building a product you want to get in the hands of millions. It's quick to read (only 140 pages), to-the-point and made a world of difference to our concept&design challenges. We used it a lot to model the behavior of our users and figure out specific areas we missed and needed to focus on in order to get engagement.
Another great value of the book is the in-depth analysis of the hooks we are subject to every day (in Twitter, Facebook, Pinterest, Instagram etc). As you go around the everyday loop you know so well from the user perspective, you see in a structured way the other side of the coin. The side of the people who know how to design behavior patterns and make others tick.
I closed 'Hooked' with a much better understanding of social&scalable products and a lot of interesting ideas for what our team is building. These came from the numerous examples and case studies, as well as the structured questions you can answer at the end of each chapter.
If you'd like to learn about habits and how they are built&changed in general, I'd recommend 'The Power of Habit' book by Charles Duhigg. If you want to understand how habits are formed in the world of technology, startups and software and mobile products, "Hooked" is the book for you. It's built on the same solid research base, yet much closer to practice and much more relevant to today's tech world.