The history of marketers seeking the advice of physicists is a short one, but an understanding of the Theory of Resonance may give communications experts the edge. Resonance Theory explains the curious phenomenon of how very small pebbles dropped into a pond can create bigger waves than a large brick. The brick makes a decent splash, but its ripples peter out quickly. A tiny pebble dropped into the same pond, followed by another, then another, then another, all timed carefully, will create ripples that build into small waves.

As Dr. Carlo Contaldi, a physicist at Imperial College London, explains, a small amount of energy committed at just the right intervals - the'natural frequency' - creates a cumulatively large effect.

Media consultant Paul Bay believes that just as with thepebbles in a pond, a carefully choreographed and meticulously timed stream of communication ( a monthly ad in MT, for example ) will have a more lasting effect than a sporadic big splash during primetime ad breaks.

Innocent is the testament to the power of pebbles. Until last year, the maker of smoothies had never advertised on TV, instead drip-feeding the market with endless ingenious marketing ploys - from annotating its drinks labels with quirky messages to hosting its own music festival, Fruit stock. The company sent a constant stream of messages rather than communicating through the occasional big and expensive noise.