...is the agency Christmas card.
Why? Well there are plenty of briefs on which creatives complain "everything's been done."
But in the case of the agency Christmas card, that might just be true.
You can see a mahoosive collection of them here and here.
So what to do?
Well, obviously it has to be something digital. You don't want to imply that your agency is a stegasaurus.
Though the irony is that although it's the most 'instant' medium, anything digital actually takes longer to make. And is often expensive.
Over the years, Mother London have probably produced the most interesting examples. The one that still sticks in my mind is this video, in which Mary and Joseph are depicted as modern-day asylum seekers, and get turned away by every hotel in London.
But that was 10 years ago.
I wonder if, by now, 'digi-card fatigue' is setting in.
Will clients and rivals truly be wowed by "a Christmas gif for you" turning up in their inbox? Or will they simply press 'delete'?
Uber-planner Russell Davies writes in his Campaign column this week: "Don’t do an agency Christmas card... no-one wants a Christmas wish from a corporation."
And he might have a point.
Especially when you consider that, for the same cost as that self-indulgent e-card, you could send every client a bottle of champagne.
I know which I'd rather get...