I had the pleasure/luck of reading this book almost at the start of my sales career, which was shaped also by a friend of Ken's, John Wright (who sadly died at the end of 2007-he is missed for his friendship as well as laser sharp, at times painful, advice)!
This book tells you all you ever really need to know about account management of key clients. In all my sales and sales management career (some 20 years now), I have yet to come across basic situations that it does not cover.
If you need advice on account management, in an easy to access format, then you should buy this book. I still read mine, and teach it to students of sales.
PS, no, they didn't pay me to write this....