There’s a dandruff shampoo advertisement on television which features a ‘dandruff swipe test’. They swipe a woman’s hair and the sticky strip comes away with loads of dandruff. Then they make the claim that after using the shampoo being advertised, that the amount of dandruff on the sticky strip is virtually non-existent.
It’s very convincing because the sticky strip comparison appears to present an obvious truth – now you see the dandruff, now you don’t. As such the mind accepts it as fact and then automatically reaches a broader conclusion – that the shampoo cures dandruff – without bothering to question further.
However, does it just wash the dandruff out without addressing the underlying medical problem? Whether it does or doesn’t, the ‘strip test’ is not a valid scientific test result, but it is believable.
It’s a bit like the copywriter’s ‘pre-supposition’ technique. Using certain words or key phrases, coupled with information delivered quickly, the writer induces the brain to accept part of the message as a fact.
For example, words and phrases such as: ‘Clearly;’ ‘as you discovered;’ ‘obviously;’ ‘it’s a known fact;’ ‘the results are clear;’ ‘Look, it’s all gone...’
If the person receiving the message has an emotional investment in the problem, the compulsion will be all the more powerful.
Personally, I prefer marketing messages based on fact. Using things like the strip test have a powerful illustrative effect, and if used as an analogy, can be very effective – provided they are underpinned by credible scientific research.
I am not saying this particular brand of shampoo does not have the credible research to back up its claims, but it does serve as a good example of how to build a strong case on the flimsiest of evidence.