Cadbury smartly homes in on one of those confusing social conventions with its new Heroes ad. A family are at the supermarket when they bump into a woman whose party they are attending later that day. “Don’t bring a thing,” she reminds them.

Clearly, as they realise, this means they have to bring something. Cue amusing flash-forwards of inappropriate gifts (including, inexplicably, a bowl of nachos), before the enormous gondola-end display of Heroes that’s in shot is inevitably turned to.

The ‘What to bring when you’re told not to bring a thing’ slogan is a bit of a mouthful, but it flows nicely enough - as does the whole ad, in fact. But is marketing your product as a last-minute, thoughtless gift solution really that wise?