This book is an interesting academic read addressing language and society. I think it, for me, was not an exciting read - but very informative.
I especially enjoyed the sections addressing gender and language. It does a great job and I remember getting hammered on a report by a supervisor during my first Masters (in TESOL) as the grader suggested that I was way off in writing that language differences are not possibly biological and are absolutely social. I was not aware the nature nurture issue was solved, and thankfully this book did ponder the thought that men and women do differ anatomically and physiologically. I was glad to be reassured here - and gender is addressed in several places.
The book goes way beyond this and looks at class, vernacular(s), and cultures from around the world. A book that all TESOL gurus should have on the shelf for the rainy day they are keen to dig in this direction. A good reference for literature reviews in your papers.