However, since there is a lot about human psychology that doesn't appear on a balance sheet, I am inclined to buy. Why? Well, as evidence, consider the Nokia 8110, Sky+, Eurotunnel, Amazon and Argos.
The phenomenon I am referring to could be called "Progressive Experience Loyalty". Whatever you name it, it exerts a spectacularly powerful force in certain categories, driving consumers to a much greater level of repeat purchase than is found, say, in packaged goods or cars. And, because it drives many of us to adopt unusually loyal behaviour, we post-rationalise this by developing strong brand engagement and brand affinity to match.
In the beginnings of the dotcom era, it was assumed online loyalty would be almost non-existent. Logic said that, since a cheaper competitor was one click away, people would adopt repertoire behaviours, making endless price comparisons and shopping opportunistically from many retailers. In reality, the opposite has happened, with a few e-tailers gaining a disproportionately large share of sales - and affection.
What this shows is the power of human habituation. Once we have invested time and effort mastering an interface, website, EPG or other system, we are reluctant to squander that sunk mental cost by defecting. People who mastered Nokia software, the Sky+ EPG or the Ocado website are markedly reluctant to squander that hard-won expertise by trying something new - any more than a golfer would change his brand of clubs each day. "Flow", to use Mihaly Csikszentmihalyi's coinage, is one part of it. Another is "loss aversion" - the fact that, in trying something new, the possible costs loom larger than the benefits.
In the offline world, airline loyalty programmes partly work because of the mental investment required to understand them. Having sussed the BA Executive Club, I'm loath to start again sussing out Malev Miles. And people who have spent years mastering cross-channel ferries are reluctant to try anything different (which is why, unexpectedly, the Brits were slower to try Eurotunnel than Johnny Frenchman).
But the most extreme manifestation of this came when I saw recent BrandZ figures on "bonding levels" with UK retailers. Easily at the top was Argos. Next, I think, may have been Ikea. Revealingly, the two retailers with the greatest idiosyncrasies inspired greatest loyalty. The harder the system is to crack, the more devoted we become - possibly the same insight which teaches women to play hard to get. (In fact "Why women are like Ikea" is the title of my career-ending speech to Wacl later this year). Research will tell you to make everything easy. Behaviourism (and sex) shows a little upfront difficulty may work better.
Rory Sutherland is the IPA president and vice-chairman of Ogilvy Group UK