Don’t expect to see Cambridge Analytica-style microtargeted political adverts driven by personal data during this general election: the tactic is now considered by many to be an ineffective “red herring” and is increasingly being blocked by social media platforms. The digital strategist Tom Edmonds said Facebook had banned political campaigns from using many of the tactics deployed in past contests. “Running a campaign aimed at 500 people didn’t earn them much money and just got them loads of shit,” he said. Edmonds, who ran digital campaigns for the Conservatives in the 2010s, said this general election would instead be defined by parties spending tens of millions on online adverts designed to reach as many people as possible. “It’s got to the stage of being like TV advertising – it’s top-level messaging.” Microtargeting is based on the idea that adverts are more effective if they are hyper-relevant to a person’s precise interests and political views. In theory, political parties could use Facebook user data to send one advert to a Lib Dem-voting dog owner who dislikes cycle lanes and is concerned about bin collections, and show a completely different advert to their Tory-leaning neighbour of the same age and gender who is mainly worried about the state of the NHS and immigration. There was particular focus on the tactic in the wake of victories for Donald Trump and the Brexit campaign in 2016, especially after reporting in the Guardian and the Observer about the now defunct Cambridge Analytica. The political consultancy made big claims about its power to swing elections and change minds through targeted political campaigns, often aided by data that it had improperly gathered from Facebook users. Much has changed since then, according to Sam Jeffers, of Who Targets Me, who has been tracking online advertising in the UK for the last decade. He said Meta, the owner of Facebook and Instagram, no longer enabled British political parties to target adverts even at precise parliamentary constituencies. “Labour are just picking a load of places in the country and saying ‘show this to everyone’. The Tories aren’t even doing any regionally targeted stuff on Facebook at the moment,” he said. There are doubts within academia about the effectiveness of the old approaches of seeking ultra-niche audiences. Ben Tappin, a research fellow at Royal Holloway, University of London, said his research had found “mixed evidence for the claim that microtargeting changes voters’ minds”. As a result, he said, microtargeting “may be something of a red herring”. This change in approach for UK political adverts – from ultra-niche targeting to smothering the internet with the same messages – has been accelerated by a little-noticed change in the law. Last year the Conservatives doubled the amount of money that can be spent by each party during a general election campaign to £34m, enabling the best-funded parties to be less picky about how they spend their money. Most of this increase is expected to go on an unprecedented online ad splurge, with Labour and the Tories each expected to spend tens of millions on online adverts over the next five weeks. Labour is already burning through more than £100,000 a day on Facebook and Instagram adverts, according to Who Targets Me analysis, with even more money spent buying adverts around Google search results. Smaller political parties such as the Liberal Democrats, Greens and SNP face being overwhelmed and are spending only a few thousand pounds on their campaigns. Tappinsaid online adverts targeted at supporters of a particular political party could be more effective. But he and his colleagues found that microtargeting of political messages according to multiple demographic factors such as age, gender, education, ideology or moral values had limited impact. Instead, he suggested a more effective technique for parties could be to test hundreds of different adverts and then pour large sums of money into the ones that resonate with large numbers of voters. Tappin accepted there were real concerns among the public about microtargeting, especially given Cambridge Analytica’s gathering of social media data without “their awareness or consent”. But these worries may have led to people overstating the actual power of microtargeting to swing elections. He said: “I think the jury is still out on whether campaigns can use detailed information about individuals to deliver highly personalised ads that more effectively persuade them. I’m sure some campaigns are trying to do this, but my reading is that we don’t have clear evidence on whether or not it’s an approach that actually works in practice.”