Only 49 per cent of online ads – both desktop and mobile – served in the UK during Q3 2016 were viewable, according to a report from ad verification company Meetrics.

The report applied the IAB and Media Ratings Council definition of a viewable ad, requiring 50 per cent of the ad to be in view for at least one second.

This is up very slightly from the previous quarters figure of 47 per cent, but the UK is far behind other countries in Europe in this regard. Viewability rates over the same period stood at 59 per cent in Germany, 60 per cent in France and 69 per cent in Austria.

“To be honest, due to the attention and initiatives focused on addressing viewability, we’d expected a bigger improvement in the UK in the third quarter,” said Meetrics director of international business Anant Joshi. “However, it seems that these efforts only just outweigh the impact of programmatic ad delivery and the amount of ad re-loading done by publishers to boost inventory levels. It’s still translating into about £615m wasted annually on non-viewable banner ads alone.”

The report also looked at video ads, which fared significantly better at 68 per cent viewability.

This is based on the standard measure for video ads – 50 per cent in view for at least two seconds – but Joshi argues that this isnt enough “to have any form of impact”. Looking instead at a minimum time of 10 seconds, the viewability rate drops to 30 per cent.