NEW YORK: The viewability of digital ads ought to be considered in relative terms, based on how fast a person typically scrolls down on their smartphone, rather than an absolute measure such as two seconds, according to Facebook.

"We've been studying this phenomenon of time spent on ads and the impact on how well an ad campaign works for a long time," Graham Mudd, director of ad product marketing at the social media giant, said in an interview at Advertising Week in New York, reported by Digiday.

He reported two findings. "One is that value is created the moment an impression is made.

"But the second thing is that value increases as you spend more time with ads. There is clearly a relationship between how much attention someone gives an ad and their likelihood to remember it."

While neither of those things might be thought revolutionary, he went on to explain that "the interesting thing is that people have hugely individualized ways of consuming content".

So, people in their teens "consume content two and a half times faster than people in their 60s", which is why Facebook has turned its attention to devising a relative approach to viewability and brand awareness optimization.

Thus, if someone is a "slow-scroller" and consumes content slowly, then that becomes a baseline, he said.

"And for a given ad campaign, if they're spending twice as long looking at that ad as they typically look at ads, then that signals to us that this must be relevant and we go and look for more people like that and use all the data we have about people, their profiles, to go find audiences."

Ad Week described this "a more precise take on data targeting for branding-minded marketers" than what Facebook has previously offered.

"With everyone talking about ad viewability, brands should find this interesting," said Mudd.

Data sourced from Digiday, Ad Week; additional content by Warc staff