The viewability of display advertising also varies significantly by platform, format and buy type. At a global level, mobile video is the most viewable format, with only 30% of ads not meeting the Media Rating Council (MRC) standard. This rate reduces to around one in five (22.1%) when the ad is bought directly from the publisher, but rises substantially – to one in two (49.0%) – when the ad is bought programmatically.

Programmatically purchased ads routinely under-perform in terms of viewability when assessed against the MRC standard. On average, 46% of programmatic ads are not viewable. One in two (52.0%) mobile web display ads do not meet the grade, while a similar proportion (45.1%) was recorded for programmatic desktop displays ads. One in five mobile display ads in app also fall short. In all cases, viewability improves when the ad is bought directly from the publisher, though the difference is more pronounced for video ads.