BOCA RATON, FL: Kellogg's has made enormous progress in determining the viewability of its online display ads – knowledge the food group has successfully tied to their effectiveness, in the form of actual in-store sales.

Aaron Fetters, director of the firm's Insights and Analytics Solutions Center, told delegates at the Association of National Advertisers' 2014 Media Leadership Conference that it had undertaken detailed analysis of this area.

Many messages, the organisation learned, were not seen by consumers – for reasons such as appearing below the fold or not being completely rendered before an internet user clicked away to another page.

"We started to find out maybe half of our ads were never viewed," Fetters said. (For more, including figures about how rising viewability boosts effectiveness, read Warc's exclusive report: How Kellogg's embraced digital visibility and drove engagement.)

"So it didn't matter if it went to that right audience. And all the work our creative teams put into coming up with great content didn't matter either."

The total reached by Kellogg's was largely consistent with research by comScore, the insights provider, which has reported that 54% of display ads ultimately go unseen by the intended target.

Breaking out its data further, Kellogg's discovered variations existed between the categories of display ads it ran. "With our first peek in there, we saw some pretty drastic differences across our executions," said Fetters.

The vertical placements known as skyscrapers typically recorded the strongest performance here, followed by banners and then square ads on digital pages.

Such fluctuations demonstrated that relying on simplistic measures, rather than drilling down into the details, is not always the best approach. "All advertising impressions are not created equal," is how Fetters described it.

Having ascertained the viewability of its ads, Kellogg's progressed to tying this metric to in-store sales, the "first time we put dollar values" against this measure. "We have proved that it's worth money," Fetters said.

Data sourced from Warc