Uh... did you read the article you just linked? "McLuhan frequently punned on the word 'message', changing it to 'mass age', 'mess age", and 'massage'; a later

Uh... did you read the article you just linked? "McLuhan frequently punned on the word 'message', changing it to 'mass age', 'mess age", and 'massage'; a later book, The Medium Is the Massage was originally to be titled The Medium is the Message, but McLuhan preferred the new title, which is said to have been a printing error."