If it were up to me, I would change the tittle of the book to "The Science of Customer Service" as I indeed found this book to be scientific in every single way. It provides facts, statistics and a guide to improving the company's customer service in order to build loyalty of its clients and increase revenue. Though I have learned a lot from this book, I find the approach to Customer Service a bit too much statistics driven (which is certainly not bad, of course), but I do find the empathy based and "acts of kindness" approach, as in Delivering Happiness, closer to my own point of view.
I found the book quite useful as an introduction to usability testing, why it is so important and how valuable it can be when performed on a regular basis. It covers the subject in details and provides a step by step guide on how to perform the testing on your own.