Feedback is a vital part of communication. When we are talking to someone over the phone, if they don’t give us the occasional ‘mmmm’, ‘aaah’, ‘yes, I see’ and so on, it can be very disconcerting. This lack of feedback explains why most of us don’t like answer phones.

In face-to-face communication, we get feedback in the visual channel as well – head nods, smiles, frowns, changes in posture and orientation, gaze and so on.

Advertisers need feedback, which they get in the form of market research from institutions. How else would they know if their ads are on the right track?

Broadcasters need feedback, which they get from agency ratings.

Politicians need feedback, which they get from public opinion polls and so on.

Perhaps one of the main reasons for the model’s popularity amongst communication theorists in the ‘humanities’ has been that it provides them with a ready-made jargon that ordinary mortals are not likely to be familiar with, as well as conferring on the subject a kind of pseudo-scientific respectability.