Court bid challenges Google’s stranglehold on UK’s display ad market worth £3.6 billion annually

A collective claim, led by technology journalist and campaigner Charles Arthur, says the tech giant has broken UK competition law in the online display advertising market where over 200,000 websites and apps have lost out on ad revenue, could benefit from up to £3.4bn in damages.

Charles Arthur, represented by global disputes-only law firm Hausfeld, has filed a claim on behalf of UK publishers of websites and apps against tech giant Google in the UK’s Competition Appeal Tribunal.

The claim centres on Google’s dominance of a sector of the UK online advertising market known as “open display advertising” - estimated to be worth £3.6bn in 2023. 1

Display ads are a widely used form of advertising which are shown when a user visits a website or uses an app. As the content of the webpage or app is downloading, advertising space is sold to the highest bidder in a near-instantaneous automated auction. The successful bidder uses data collected from the user’s previous online activity to show them adverts for goods or services they are more likely to be interested in.

The UK’s Competition and Markets Authority has found that Google controls between 50% to 90% of the complex intermediary markets in “ad tech”, which connect advertisers to publishers who are selling display ads.2

Because of its dominant market position, Google has been able to unlawfully restrict competition by favouring its own ad tech services and charge inflated prices to publishers since at least 2014. This has raised prices for ad tech services across the entire market, with the result that all publishers, including those who use Google’s rivals’ ad tech services, have suffered losses of up to 19% of their revenue. Many publishers, such as local news websites, depend on advertising revenue to survive.

Charles Arthur, who is proposing to represent the UK publishers, explains why he has taken a stand against Google with this proposed collective proceeding:

“I see the dominance of Big Tech companies as one of the major problems faced by modern society. Google has inserted itself between advertisers and publishers in the online display ad market by riding a wave of technological development that it claims has brought benefits to publishers. This is not true: as a result of Google’s conduct publishers have suffered losses running into billions of pounds. The UK Competition and Markets Authority is currently investigating Google’s anti-competitive conduct in ad tech, but they don’t have the power to make Google compensate those who have lost out. We can only right that wrong through the courts, which is why I am bringing this claim.”

Luke Streatfeild, Partner at Hausfeld in London, who is leading the litigation on behalf of Mr Arthur, said:

“Our client, Charles Arthur, is claiming that Google dominates the UK online display ad market and abuses its position by excluding competition and charging inflated fees. We look forward to working with our client to return compensation to websites and apps who have lost out, and to help to put a stop to Google’s anti-competitive conduct in the future.”

Google’s behaviour has also come under scrutiny in other jurisdictions. For example, in June 2021, the French competition authority concluded that Google had abused its dominant position in the ad tech market. Google did not contest the decision, accepted a fine of €220m and agreed to change its conduct.

UK publishers who are interested in finding out more about the claim should visit and sign-up for regular updates regarding the progression of the case.

Charles Arthur has secured third-party litigation funding to bring the proposed claim and insurance in respect of Google’s costs of defending the claim, which means affected UK publishers will not pay costs to participate in this legal action nor will they have any financial risk in relation to Google’s costs. 

Charles Arthur is represented by Hausfeld & Co. LLP in London, and a team of barristers: Gerry Facenna KC, Nikolaus Grubeck and Alison Berridge of Monckton Chambers and Greg Adey of One Essex Court. 

Before Charles’s claim can proceed to trial, the Competition Appeal Tribunal will need to approve him to (i) act as class representative and (ii) bring the claim as an opt-out collective claim.


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[1] Based on figures from the IAB UK and PwC’s “Digital Adspend Study” and the AA/WARC Expenditure Report, “UK Ad Market’s Covid Recovery Continues But Forecast Growth Slows”.
[2] Competition & Markets Authority, “Online platforms and digital advertising market study”, at Tables 5.3 to 5.6.  

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