This book is unique in the group of information that you can find online, is an excellent book that guide you from the start  to finish with any software product.The  most interesting part, is that the book guide you on selecting a niche so you can sell more and faster... also the book will show you the right way to test your market before spending hours and hours of development just to find out that nobody wants your product.I think Rob Walling is a master in this topic, because the way he wrote the book, very focused to the point and based on the products that he have finished in the past.I recommend this book to any entrepreneur or software developer that enjoy selling and making money online.Congrats Rob!!!!