Online ad viewability levels in the UK dropped to 50 per cent during Q4 2015, according to a report from Meetrics, down from 52 per cent the previous quarter.

This is based on the IAB and MRC viewability standard, which states that 50 per cent of the ad must be in view for at least one second.

“Although the drop isn’t much, it’s the direction that’s more important,” said Anant Joshi, Meetrics’ director of international business. “Current efforts to address the issue don’t seem to be working – either that or the efforts in one area are simply offsetting the inevitable falls generated by more automated buying. In Q4, around £134m was wasted on unseen banner ads alone.”

The same pattern continued across Europe, with viewability rates dropping from 61 per cent to 58 per cent in Germany, from 69 per cent to 65 per cent in France and from 70 per cent to 65 per cent in Austria.

The report also looks at how various ad formats fared in the UK, with half-page ads proving the most viewable (at 63 per cent), followed by billboards (59 per cent), while leaderboards are the least viewable format (43 per cent).