Marshall McLuhan, Understanding Media: The extensions of man, 1964.

The copy [of an ad] is merely a punning gag to distract the critical faculties while the image of the [product] goes to work on the hypnotized viewer. Those who have spent their lives protesting about 'false and misleading ad copy' are godsends to advertisers, as teetotalers are to brewers, and moral censors are to books and films. The protesters are the best acclaimers and accelerators. Since the advent of pictures, the job of the ad copy is as incidental and latent as the 'meaning' of a poem is to a poem, or the words of a song are to a song.