MOUNTAIN VIEW, CA: Video ads are more likely to be seen than display ads, but not by much, according to new Google research.

A study of video ad viewability on its platforms used the standards set by the Media Rating Council and IAB: 50% of an ads pixels must be visible on screen for at least two consecutive seconds. It found that, outside of YouTube, the average viewability of video ads across the web was 54%.

YouTube, owned by Google, fared much better in this research, with 91% of ads on this platform meeting the required standards. It is also, of course, a video destination where pre-rolls are far more likely to be seen by consumers.

Late last year, Google reported that only 44% of display ads were seen, as measured by the same industry body standards: a viewable impression occurs when 50% of an ad's pixels are on screen for one second.

The reasons most video ads are not seen was simple: three quarters (76%) were running in a background tab while users focused on something else or not on screen at all. The remainder were scrolled off screen or abandoned in less than two seconds.

But even when video ads aren't viewable they can still have an impact if they are audible. Google said YouTube users exposed in this manner had 33% more ad recall than a control group who didn't experience the ads at all.

Viewability rates were found to be higher on mobile devices (83%) and tablets (81%) than on desktop computers (53%), although once again Google claimed much higher levels on YouTube.

The size of the video player and the location of the ad unit on the page were also important factors in whether an ad was viewed or not.

Separately, Will Doherty, vp/business development at Index Exchange, argued in Ad Exchanger that viewability correlates to influence, impact and engagement with one's audience and that rather than being a fixed metric should be seen as a currency.

Exchanges would then "become the neutral facilitators between buyers and sellers and support all currencies to allow both sides to create deals based on a common and agreed-upon tender", he said.

Data sourced from Google, Ad Exchanger; additional content by Warc staff