This book provides a very good and comprehensive insight into open relationships of any kind - from sanctioned infidelity to equivalent relations with multiple partners simultaneously. The authors are not trying to proselytize, but represent possibilities and show ways, but also speak clearly potential problems and offer solutions. They are not restricted to facts, but also deal with very intense the emotional significance of different concepts.
Therefore, the book is intended both to interested people for whom the topic Polyamory is completely new, as well as to people who already have experience and want to expand their horizons.
I personally feel that it is one of the best books on the market on this subject.