Maybe it's time to free advertising from the need to represent the entirety of the brand idea and recognise that other disciplines are capable of doing this in a richer and more rewarding way. In particular, for many brands it's their online experience that should be delivering the big brand idea in all its technicolour glory. Advertising, whether offline or digital, is always sharper when it has latched onto a specific business problem rather than wafting around conjuring up beautiful brand worlds.

The bad news for ad agencies would be the decline of the set-piece brand ad as the discipline got back to the job of selling. Seeing advertising recast as the new below-the-line discipline is unlikely to be popular in Soho.

On the other hand, the good news for ad agencies is that few of the brand's other business partners can frame the big idea in the first place. And this remains the most serious challenge for standalone digital agencies in the era of the big brand idea.

Digital may be one of the very few marketing disciplines that can cope with the enormous bandwidth of today's ideas, but unless those agencies have the intellectual and creative firepower to conceive of the idea, they'll struggle to usurp the traditional ad agency as the primary brand partner.