The level of online ad viewability in the UK has dropped noticeably over the last year, in the face of the rise in automated ad buying processes, according to a new report from European ad verification company Meetrics.

In Q2 2015, less than half (49 per cent) of online ads served in the UK met the IAB and Media Ratings Council’s recommendation that an ad is considered viewable if 50 per cent of it is in view for at least one second. That’s down from a viewability figure of 56 per cent in Q2 2014.

The UK figure of 49 per cent is well below that of Germany (64 per cent) and France (62 per cent), where automated ad buying techniques, such as programmatic, are less dominant. A recent IAB study (Media Owner Sales Techniques), showed that 45 per cent of UK display ads were bought programmatically in 2014, up from 28 per cent in 2013. The IAB predicts this will rise to 70-80 per cent by 2018.

“There’s no doubt programmatic brings many benefits to advertisers but there’s a flip side to every coin,” said Anant Joshi, Meetrics’ director of international business. “It’s certainly less transparent than buying directly and there’s also a big question mark about the quality of much of the inventory sold this way and, clearly, that most of it never ends up being seen.

“Cross-referencing our data with the IAB’s 2014 digital ad spend report suggests around £485m last year was spent on display ads that weren’t seen. So, it’s vital that agencies, on behalf of their advertiser clients, demand more accountability from the vendors and middle men used to buy their media. One way is to ensure any vendors are rubber-stamped by JICWEBS that they meet industry-agreed standards for online ad trading.”

The report also showed that Leaderboards were the least viewable (40 per cent) ad format whilst Billboards (68 per cent) and Skyscrapers (60 per cent) were the most viewable. Furthermore, for ads that met the 50 per cent/one second viewability rule, the average time these ads were in view was 29.5 seconds.