Many ads fail to reach their intended audiences, according to a study by Nielsen. The study found that only 53 per cent of ad impressions served in the UK were viewed by people of the age and gender that advertisers had wished.

Mobile (52 per cent) and desktop (53 per cent) performed equally well when attempting to reach broad audiences but mobile campaigns were more accurate in targeting narrower ones.

The accuracy of ad targeting does, however, vary significantly between sector. Travel marketers reach their desired audience 66 per cent of the time, followed by entertainment on 64 per cent. Retail, at 42 per cent, and FMCG, at 40 per cent, struggle the most at hitting their target audience.

“Although 100% accuracy is likely to remain a pipe-dream, a school report on digital technology’s ability to hit specific audiences might read ‘could do better’,” said Barney Farmer, Nielsen’s marketing effectiveness director in the UK & Ireland. “However, in fairness it’s more precise than traditional media and performance is improving all the time, particularly on mobile whose superiority in reaching narrower audiences reinforces its status as the most highly personal ad medium.”

The study of nearly 3,400 UK campaigns, run between April and June 2016, also found that buying directly from a website publisher is slightly more accurate (55 per cent) than buying via a third-party ad network (52 per cent)

The overall success rate of the UK was 53 per cent – putting the country lower than Germany (58 per cent) and Italy (57 per cent) but significantly higher than France (43 per cent).