24.03.2021 06:00 AM

Google’s rivals are fighting back against Chrome’s big cookie plan

Next year Chrome will ditch third-party cookies used in online advertising. But new contenders are emerging

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Google is about to fundamentally change how the web works. Sometime in 2022, most likely during the first six months, its Chrome browser will ditch the third-party cookies on which much of the digital economy is built.

The plan to replace cookies is controversial. But Google is not alone. Threatened by the upcoming changes, rival browsers, advertising tech companies and open web advocates are competing to build alternative systems that could stop Google from getting everything its own way.

Companies are experimenting with email-based tracking systems, directly gathering more user data and reviving unloved forms of contextual advertising. Microsoft, which owns the Edge browser that’s based on Google’s Chromium, is another major challenger. While Google is putting Chrome at the centre, Microsoft is pushing to improve anonymity in the existing ad sales setup.

Google’s plan to stop third-party cookies in Chrome is a big deal. While Apple’s Safari and Mozilla’s Firefox browsers put restrictions on the tracking method years ago, neither have Chrome’s clout. It’s the world’s biggest browser and Google – unlike Apple or Mozilla – also makes most of its money from advertising. As well as sending shockwaves through the advertising industry, the changes will also impact publishers who let people read articles for free by showing them targeted advertising.

At the moment third-party cookies in Chrome follow you around the web, track your browsing history and send this data to advertising networks. People are represented by strings of numbers that act as IDs and allow websites to show targeted advertising. The theory goes that if you’re seeing ads for things you like then you’re more likely to click on them and buy something.

But people don’t like their browsing history being tracked and change is widely considered necessary. For Chrome this comes in the form of its Privacy Sandbox – a set of proposals for replacing cookies without destroying the online ad industry.

Part of this is a machine learning system called Federated Learning of Cohorts (FLoC), which analyses web activity within Chrome, not Google’s data centres, and lumps people into a group with others who have similar interests. Adverts can then be shown to these larger groups, called cohorts, which are not based exclusively on one person's behaviour. Other parts of the proposal cover different types of advertising.

Google’s system puts Chrome at the centre of the advertising process, including the way companies bid on which ads to show. It’s a radical change in the way the current system operates. Microsoft’s counterproposal, called Parakeet, uses the browser to anonymise people’s information before passing it through the existing behind-the-scenes systems where bids are made and ads are sold.

“We are still in the early stages of this journey,” a Microsoft spokesperson says, adding that the company is working with the industry and standards bodies on its proposal. Google is developing Privacy Sandbox in the same way and both companies say they are committed to working with the advertising industry to make more privacy-focussed alternatives to cookies.

Regardless of who wins the tug-of-war ads that are based on people’s behaviour aren’t going away. First-party data, which is collected by the websites you visit, is seen as one way to using personalised adverts.

Your email address, for example, could instead become a key way to help determine which adverts you see online. While Google says its systems won’t use “alternate identifiers to track individuals”, the advertising industry is working on other options that emulate the behaviour of third-party cookies.

The proposals come with one significant difference: people must sign-up to these advertising systems and give their permission for ads to be targeted specifically at them. One alternative is Unified ID 2.0, an open-source system being created by The Trade Desk, a tech and software company. Unlike Google’s plan, Unified ID 2.0, which will eventually be operated by an independent company, creates an identifier for each person who logs in with their email address. They can then set interests for the types of ads that they want to see on websites that use the system.

“That ID number is then used with your parameters attached to it to then be able to target advertising,” says Philippa Snare, senior vice president EMEA at The Trade Desk. She adds the system gives people control over the advertising they are shown and doesn’t rely on “having one or two companies controlling that”. So far BuzzFeed, Newsweek, Foursquare and Comscore are involved in the project and more than 50 million people are taking part in a beta trial of the advertising technology.

But email-based systems are also proving controversial as they’re still linked to people’s personal information. Google has dismissed replacing cookie systems with email IDs, saying that such systems fail to “meet rising consumer expectations for privacy” or the scrutiny of regulators. (Google’s Privacy Sandbox proposals are being investigated by the UK’s Competition and Markets Authority).

Old advertising tech is also being revived. Artificial intelligence and machine learning is making contextual adverts, which are based on the content of a page, more sophisticated. “We are already successfully testing contextual targeting in production with very encouraging results,” says Ingmar Zach, a senior vice president at personalised ad firm Criteo. Zach says deep analysis of web pages can give advertisers an understanding of who the article is about, if products are mentioned and its overall sentiment. Criteo is comparing this with historic data, gathered from third-party cookie use, to make the advertising more effective.

Chrome’s browser rivals are also developing more powerful contextual advertising systems. Russia’s Yandex browser, which has a higher domestic market share against Google than almost any other browser in the world, is using deep learning to improve its understanding of pages. “Contextual targeting relies on website content, rather than user characteristics,” a company spokesperson says, adding it has recently introduced tools to control third-party cookies, and is also working on more first-party data being used in its advertising network.

“We're probably going to see a future that is not so singular,” says Joanna O’Connell a vice president at Forrester. She predicts that advertisers will probably use a mix of Google’s own tools – its position at the centre of the industry is unlikely to be weakened – as well as those of others. Not every company will survive the changes though.

“There will be many parts of ecosystems that face a reckoning,” O’Connel says. “They won’t make it because they are operating under models that are not sustainable, or because they are independent and don’t have any particular unique asset that makes them special in this new world.”

Matt Burgess is WIRED's deputy digital editor. He tweets from @mattburgess1