How consumer habits are subject to the law of unintended consequences

Some time in the 1960s, a group of people in an advertising agency (among them Llewelyn Thomas, son of Dylan) found themselves debating the direction of causation in the purchase of electric drills. Their dispute revolved around one question: do men a) conceive a need for making a hole and therefore go and buy a drill or b) buy an electric drill in a shop because it looks cool and then wander around the house desperately looking for any excuse to make holes in things.