The study, by InSkin Media, Research Now and Sticky, involved tracking the gaze of nearly 4,300 consumers while tracking the viewability of ads. 

It revealed that 25% of ads defined as ‘viewable’ by meeting minimum industry guidelines are never looked at. Only 42% are looked at for at least one second. The median time a viewable ad is actually gazed at is 0.7 seconds. 

The study demonstrated how long an ad needs to be viewable in the first place to reach certain levels of gaze time: on average, to be looked at for up to a second an ad needs to be viewable for 14 seconds. Ads achieving at least one second of gaze time are viewable for an average of 26 seconds. 

The study also looked at how gaze time and ad recall differed by ad format and level of clutter. Page takeovers had highest gaze time, at 7.5s, and highest ad recall at 52%. Billboard ads were gazed at for 3.3s ( 23% ad recall), half-page for 0.9s ( 21% ad recall), and MPUs for 0.7s ( 18% ad recall). 

In cluttered scenarios, ad gaze time was found to decrease by 37% on average across the formats. Page takeover formats weren't affected, but clutter caused ad recall to drop by an average of 20% across the other three formats. 

“Publishers must tread the fine line between more ads which drives more revenue, on a CPM basis, or less ads which mean stronger results for advertisers and a better user experience," said Steve Doyle, InSkin Media’s CCO.

"It’s obvious which one is most conducive to long-term loyalty from clients and readers.”