We humans love seeing choices or lists presented in groups of three. Three gives a natural balance to things, as does five or seven.
But three really is the magic number for marketers and copywriters.
A recent study for the Make-A-Wish Foundation sought to find the messaging sweet spot for securing charitable donations. They randomly assigned a different set of reasons to research participants, each of which was designed to persuade them to part with their hard earned money.
One group received two egoistic reasons to give, another received two altruistic reasons to donate, and a third received all four reasons combined. Those in the last group, who were presented with four reasons to give, were less likely to donate than the other groups who received just two. It seems that at a count of four, the attempt to persuade had been too obvious, resulting in the participants actually being dissuaded to donate.
In another test, subjects were shown ads for a brand of shampoo that carried between one and six benefit claims. Those who were given an ad carrying just three claims rated the shampoo more highly than those receiving more or fewer claims. Again, it would appear that one or two benefits are not quite enough to persuade us, yet four or more start to feel like desperation, resulting in scepticism that throws into doubt the veracity of all of the claims.
So, next time you’re trying to persuade someone, keep your list of reasons why they should believe you to three. Simple. As. That.
Source and further reading: Influence at Work blog