Advertising Platforms
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Google’s third-party cookie alternative: Topics to replace FLoCs 

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The latest development in Google’s efforts to find a third-party cookie replacement involves the dropping of its FLoCs solution and the introduction of Topics. Both support interest-based advertising, but following privacy concerns around its cohort approach, Google has substituted a solution driven by browser activity and domain categorisation.


  • As Google’s self-imposed deadline to cut third-party cookie targeting from the Chrome browser gets closer, the search to find a definitive replacement continues. The FLoCs interest-based targeting solution, formed around anonymous groups with common interests, has been killed off in the face of mounting privacy concerns.
  • In its place, Google has introduced Topics, an ad targeting solution that remains focused on user interest, but instead of targeting ads against aggregated group data, it will rely instead on recent browser activity. Ads will be targeted according to user interest inferred from site visits and categorisation of domains.
  • The development of the new approach has been informed by industry feedback from earlier FLoC trials. Google’s Privacy Sandbox lead Ben Galbraith said:

This whole process of sharing a proposal, doing a trial, gathering feedback and then iterating on the designs – this is the whole open development process that we wanted for the Sandbox and really shows the process working as intended.

How Topics works

  • With Topics, the Chrome browser will learn a user’s interests as they move around the web. To understand a user’s interests, Google will categorise sites against a limited number of subjects. Google is testing the system against 300 – 350 categories, but has indicated that this number is likely to increase as tests progress.
  • Data is stored in the browser for three weeks. When a user visits a site that supports the Topics API, their browser will share three Topics of interest, selecting one randomly from each of the user’s weekly top five interests.This data can be used by the site’s advertisers to target the user.
  • Acknowledging the privacy concerns with FLoC, Google says Topics will be easier for users to understand and give them far greater control. Users will be able to review and remove Topics from their lists and turn off the Topics API if they want. It will also be easier for Google to control targeting against sensitive topics, gender and race will not be included, for example.

Privacy benefits

Although dubbed FLoC 2.0 in AdExchanger, the new solution is being touted as an improvement on the privacy front.

The worry was that cohort information could be extended to allow identification of individuals. This problem is removed in Topics, where the number of categories shared is limited and the information websites receive altered regularly.

On AdExchanger, Allison Schiff compares Topics to third-party cookies that allow advertisers to track users and build profiles to understand their interests. With Topics, the browser shares a brief list of advertising topics that might correspond to a user’s interests. Schiff said:

Less data is available for targeting, and the data expires much more quickly.

Of course, it remains to be seen how the advertising and publishing industries will react to this latest solution to the third-party cookies replacement conundrum. Some publishers remain skeptical of Google’s efforts, saying whatever solution is adopted, it will benefit Google and put them at a disadvantage.

Watch this space for industry reaction and news on how the Topics tests proceed.

This piece was originally published in Spiny Trends and is re-published with permission. Spiny Trends is a division of, a content analytics and revenue generation platform for digital publishers. For weekly updates and analysis on the industry news you need as a media and publishing business, subscribe to Spiny’s Trends weekly email roundup here.