LONDON: Some 54% of online ads are not seen by their intended recipients, but optimisation can deliver a 50% uplift in viewability, an industry specialist has argued.

Infectious Media, a real-time advertising business, collected data from campaigns it delivered across sites in France, Germany and the UK earlier this year and produced an infographic to highlight its findings.

"With a move to marketers only paying for adverts that are seen, this infographic highlights a sea of change in online advertising," said Attila Jakab, Client Services Director at Infectious Media.

In all, seven key reasons were spelled out for ads not being seen. These included ads loading out of view with users not scrolling, not loading in time, plug-ins not being supported, fraudulent practices, ad blockers, tab switching and non-fraudulent bots.

Fold position was identified as a key predictor of viewability, with 49% of viewable ads appearing above the fold and 30% below. The subsequent performance of an ad was tied to exposure rather than frequency, said Infectious Media.

The report further noted that the duration of impressions was highly variable and suggested that exposure capping was an effective way to drive performance while at the same time ensuring that audiences did not become exhausted by an ad.

Marketers should also favour inventory with higher viewability rates as this too delivered a better campaign performance, with the 50% uplift in views already mentioned and an increased likelihood that viewers will take action by clicking through.

"Brand marketers are able to use this approach to safeguard the quality of their advertising inventory, whilst performance marketers can benefit from the increased response that is triggered by more viewable advertising," Jakab said.

The debate around the viewability of ads was further complicated recently when Sticky, a company that uses webcams to track users' eye movements as part of its research, claimed that just 14% of ads were actually seen, compared to the 46% that were viewable.

Data sourced from Infectious Media, MediaPost; additional content by Warc staff