Metaphors are the transfer of meaning between two subjects often to create a more poignant effect and as such, metaphors are an excellent way of getting across a feeling and image in a creative way.
In creative writing metaphors are used to a richness and depth to prose, having a comparison between deceptive matter, that the reader has to make mentally, in text often enables the reader feel more involved and closer to the text e.g Buwokski (Charles Bukowski author of Post office and ham on Rye) often used metaphors to add a poetic depth to his drunken pits of despair i.e 'My beer drunken soul is sadder than all the dead Christmas trees in the world!'.
In advertising metaphors are often used to create a visceral and sensual link to the audience. On its cheapest level 'sex sells' advertising will endeavor to make people desire something by dowsing it in sexual metaphor and desire itself. fresh food adverts often carry a sexual/sensual undertone with metaphorical references e.g The recent Marks & Spencers food adverts in the U.K which feature slow motion shots of drizzling sauces onto fresh fruit and food stuffs with a semi-ecstatic voice over from a sultry woman.