The "no nonsense" football advert for John Smith's bitter in the UK follows the hot new trend of ambush marketing. However, one of the original practitioners of the art, Nike, believes the beer adverts are ambushing its own brand - and is now threatening legal action. Having let the genie out of the box, Nike will find itself powerless to avoid being ambushed itself. 'Ambush' marketing, the practice of making adverts that associate the product with a prestigious event, cause or company where no such official association exists, has become increasingly popular in recent years. For much less than the cost of official sponsorship, companies can reap the benefits.