Synthesized answer
The provided passages do not contain enough information to answer the question about the practical implications.
The passages are solely the title page of the book "Rare Marshall McLuhan / Understanding Media The Extensions of Man 1964 - NY by Marshall McLuhan" [1]. Therefore, no content from the book itself is available to address the practical implications.
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
Title: Rare Marshall McLuhan / Understanding Media The Extensions of Man 1964 - NY by Marshall McLuhan