The concept of changing the sales approach to focus only on the customers that are ready to buy now is excellent. The qualification process can certainly improve a lot, and this book gives several radical ideas about how to do it.
Unfortunately, the way these ideas are presented -- primarily through conversations between a new salesman and his co-workers and customers -- doesn't do justice to them. Most of the dialogues are artificial and lack credibility, and they detract from the main points.
There are also many factors in a sales process that are not considered (for example, the approach that is necessary to use in complex sales situations in order to sell to various levels and roles within an organization).
This book could have been better written in a similar fashion to the "One-minute Manager": it would have been shorter, crisper, and easier to understand.