tom says:

Ah...But how to keep your wits about you! This is, i think, where the psychology of marketing and possibilities for individual freedom intersect - no trick used by marketers is coercive, neither are they usually very smart. I know that aftershave adverisers, say, are just trying to make me associate their product with an astonishing success with members of the opposite sex - and if i'm really thinking about this I can see it for as laughable a proposition as it really is.

But the point is: who has time to think, all the time, about every single consumption choice they make? Answer: no one. We don't have the mental resources, or time, to 'keep our eyes open' to every trick the advertisers pull. Especially in situations, like supermarkerts, where we are in a hurry, often harrassed and with a limited set of priorities (eg "buy dinner", "get home in time for 8").

Individually, given time, we may all be fairly rational decision-makers, but aggregate us into a time-pressed, distracted, crowd and there's easily enough collective irrationality to keep the advertisers well-funded.