Subliminal advertising, currently banned, does actually work, say researchers at University College, London.

In a recent study 50 participants were shown a series of words on a computer screen for a fraction of a second, too short a time to be clocked consciously. The words were either positive (flower, peace or cheerful) neutral (box, ear or kettle) or negative (murder, agony or despair). Recognition was high, particularly for the negative words.

The current ban is due to fears that the process could be used for political ends.