Figures revealed today show that almost half (48 per cent) of online adverts do not reach the right people across France, Germany and Italy, and the U.K. The statistics, from Nielsen’s Digital Ad Ratings service, are likely to mean that billions of online marketing dollars are being wasted. Europe as a whole spent €36.4 billion (US$37.9 billion) on digital advertising in 2015, according to the Interactive Advertising Bureau. The consumer packaged goods sector fared the worst when it comes to ad impressions – or the number of times an online ad is seen by an audience – with only 42 per cent of campaigns reaching the people they were aiming for. Adverts for cars also fared poorly, with 45 per cent reaching their intended audience, followed by those for computers and electronics, and shopping and retail (both with 49 per cent). The best-performing sector is travel, where 65 per cent of online ads reached the right people. Nielsen’s figures also show that advertising via desktop computers fared slightly better than those shown on mobile devices, reaching just over 53 per cent of the intended audience versus almost 50 per cent for mobile. Campaigns aimed at people aged between 35 and 64 were more likely to reach the right audience, with 54 per cent of ads reaching them, versus those aimed at younger people. 44 per cent of online ad campaigns aimed at 18 to 34 year-olds were seen by them. “Although 100 per cent 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. But Farmer praised digital advertising’s ability to reach people more effectively than other media. “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.” Consumer packaged goods – 58 per cent Automotive – 55 per cent Computers and electronics - 51 per cent Shopping and retail – 51 per cent Entertainment – 43 per cent Financial services – 43 per cent Business and consumer services – 40 per cent Travel – 35 per cent Figures are for France, Germany and Italy, and the U.K. and are for Q2, 2016, released by Nielsen on Thursday. Follow CNBC International on Twitter and Facebook .