As someone who makes his living trying to use my understanding of the media, I really ought to have read Marshall McLuhan's magnum opus "Understanding Media: The Extensions of Man" long before now.
..and as a fan of Patrick McGoohan's "THE PRISONER (1967) - The Complete Collection
" again I really should have read it by now as McLuhan's concept of "The Global Village" clearly had some influence on the naming of Number Six's `Village' prison.
"Understanding Media" was first published in 1964, a year after I was born, and decades before mass public access to the internet, but his insights into how every form of media, then and now, shapes us all by the very nature of those media and not just the content of those media remain powerful and very applicable.
Of course he gets the odd prediction wrong, such as suggesting that cars will be replaced by something else by the 70s, but really the book is much less about predictions and more about showcasing concepts that are applicable both to what existed then and what media was yet to become whatever its shape. The book also stretches the concept of media beyond mere information exchanging tools into things which offer "extensions" of man.
Yes there are concepts that don't entirely stand up. His division of media into a continuum of "hot" and "cold" seems laboured, and even defensive, but even that has a core of truth and useful insight about it.
However the core idea remains as strong today. "The medium is the message". Of course folk like myself in the PR business don't entirely go with the idea of totally ignoring the content of a medium. We do quite like our target audiences to get our individual content messages - but yes we also have to accept that the medium delivering that content has its own society wide message too......