Back in the 1980s, the American business guru Tom Peters came up with the advice to companies to ‘under-promise and over-deliver’. The idea behind it was that there was an asymmetry in customer responses to service standards which depended on what they had been guaranteed. A long delivery time could, for example, be perfectly acceptable to them unless they had been promised the purchased item sooner, in which case the reputation of the company involved would be badly harmed.