I found this book in a second-hand bookstore for under one dollar. Had never heard of it, had never heard of him but I am fascinated by the media, specifically advertising. I wore this book out and replaced it with the new edition from MIT Press. I love this book. I still can't understand it in places (this makes me study it even more to try and understand where he is coming from) but it definitely changed the way I view the media and my place within it. We are definitely beyond being influenced by the media; the media has become the ground from which we operate.
The book is challenging and it is scattered and chaotic but there is a cohesiveness to it. I suppose that style of writing was supposed to be symbolic of the way the world is (or is becoming). This book will help you to regain your ability to reintegrate yourself with the real world and stop living life as if you have "autoamputated" your true self only to watch it live on television.
While many of the analogies are "out there," most are poignant and relevent. One example is McLuhan's interpretation of the Narcissus myth from Greek mythology. Narcissus did not fall in love with his own reflection. Narcissus had no idea that the reflection he saw was himself; he thought that what he saw was something other than himself. He became transfixed by the image; it was not love, it was numbness. The television screen is our reflection; we are not separate from it -- it is merely what is inside of us extended to the outside for us to look at, thus the subtitle, The Extensions of Man. We have become Narcissus; the media is the reflection we see and, instead of falling in love with the reflection, we have become numb, forgetting (or not aware) that what we are seeing is really us. Tell me that is not relevant today.