Although subliminal advertising is not currently practised, the deliberate insertion of commercial products as props in various forms of entertainment, especially film and television, is increasingly sought. Cinematic product placement became common in the 1980s and has now become rationalized as a specialized branch of advertising. Increasingly advertisers recognize that movies are an alternative advertising and promotional medium with an essentially captive audience. Corporations may gain control (or fund producers) of entertainment in order to be able to influence the content of the film, building in verbal or visual plugs for specific products. Such plugs need not be overt since the effect may be achieved through positive associations with the star or with the emotions aroused. Such vehicles are also deliberately used to build negative associations around a competitor's product by ensuring its presence at a negative moment in the film.