Ad formats determine how an advertisement is displayed and where it can appear. The basic ones are text ads in search, image ads in the form of banners of various sizes, video in several lengths and aspect ratios, and responsive formats, into which the advertiser supplies individual elements that the system then combines itself. The practical consequence is that a missing format means a smaller reach – if a company does not supply a vertical video or a square image, the ad will not be shown at all on some placements. When preparing assets, it is therefore worth creating materials in all the required sizes at once and supplying several variants of both text and visuals, so that the system has something to choose from. Creatives must be rotated, because their effectiveness declines with repeated display.
See also: Creative fatigue, Ad testing, Vertical video.
