This book is clearly written and will be easily understood by anyone working in a callcentre [or in customer service], from an order entry agent to a customer service manager.
It has some use useful tips, however as I have now worked in a call centre for 10 years I found some of the information to be "common sense".
It is priced reasonably as some basic [very basic] training packages contain less useful information but cost a lot [very lot] more.
Handy to keep in your desk draw as a reminder or quick reference tool. May also be useful for quality monitor staff working within call centres.