The Book is about the value and the perception of it from the view of a customer.
The book has some nice case studies describing the problems with the measurement of the value; and it gives some nice advices on how to do it properly.
You can use those results later, for your positioning and strategy development.
The main idea is, that you should not only measure the absolute value created by your company, but also the relative value in comparison to your competitors, or as in the Cinzia Parolini's book, the differential value.
Because the customer will in most cases, compare you with some standard and also, will look for the novelty.
Thus, just because they are happy with your service at the moment, does not mean that they will not switch to other companies, if they offer a better value than you.
It may seem as a common sense today, but many companies still think in absolute terms.
As much as I liked the book, I have to say, there are better options available nowadays, but one may read this one as a look back in a history etc.
If one needs other books on this topic, I may recommend the books from Art Weinstein, Morris Holbrook and Cinzia Parolini (Her book has a nice part on this topic, at the end of the book)
Managing Customer Value: Creating Quality and Service That Customers Can See (英語) ハードカバー – 1994/3/28
Bradley T. Gale is president of Market Driven Quality Inc. He served as Overseer for the Malcolm Baldrige National Quality Award during its first three years of existence, and currently is on the Steering Committee for the Conference Board's Total Quality Management Center. Gale is coauthor with Robert D. Buzzell of The PIMS Principles (Free Press, 1987), which has been translated into four languages.