The Diderot Effect refers to the way a newly purchased product fails to deliver on the happiness it promised, and instead causes our other possessions to suddenly look timeworn and in need of replacement. It takes its inspiration from an essay by the enlightenment philosopher Denis Diderot in which he laments how a new dressing gown has made his other clothes look like rags and he suddenly feels “discordant.” How to put this psychological weakness into play? In much the same way Ikea or any home goods retailer does: Through suggested add-ons. (“Now that you’re ordering that new dining table, shouldn’t you consider those plates, too?) Is it manipulative? We’d argue not. It’s not your fault a stylish new pair of sunglasses is suddenly making his readers look beaten up and, let’s be honest, when you take a close look, a little shabby. “I was the master of my old dressing gown,” Diderot laments in the end. “But I have become a slave to my new one.”
