Google has announced FLoC 2.0: “Topics API”

The Topics API Process – How will this work?

The new system will generate a top 5 (by frequency) list of interest topics for each user each week, based on the user’s browsing history. These will be generated strictly within the user’s device and will be selected from a public-facing, human-curated topics list designed to avoid what Google calls ‘sensitive’ areas such as race, sexuality and religion. The list currently contains around 350 topics which Google state will help to reduce the risk of fingerprinting, with this number set to increase by hundreds, or even thousands, as the development progresses.

Following concerns with FLoC that information could potentially be shared beyond what was intended by the parameters of the framework itself, the browser will also record which advertisers are permitted to be informed of each topic. This privacy-focussed control requires an advertiser to have been previously present on a page associated with a particular topic in order to receive subsequent notification of that same topic.

Interestingly, the first time in each week a user visits a particular website, the browser will generate a list of three topics. This list will be created by selecting a random topic for each of the three previous weeks, and serving these three topics in a random order. As per the above paragraph, advertisers will then be shown the subset of these three topics that they are permitted to see. However, for each topic the advertiser is provided there will be a 1-in-20 chance that it is replaced with an entirely random alternative. This has the stated goal of introducing some ’noise’ to the topics relating to an individual, as well as ensuring that each topic has a minimum number of members, in each case intending to avoid the possibility of being able to, directly or indirectly, identify a user (“K-anonymity”).

Each user will be able to see the 15 topics recorded for them across the previous weeks, including a human-readable description of each. In the blog post, Google set out that it is building user controls that will allow users to delete any topics that they do not wish to be shown. The topics will also be deleted if a user clears their history, and the user will be able to turn off the procedure entirely (making the API return an empty list of topics). Equally, specific websites can elect to opt-out from Topics, both in the context of generating specific topics for individuals, and advertising on that basis. During the trial stages, this will have no negative impact on a website but it is unclear in the longer term the extent to which alternative methods of user profiling will be supported in Chrome.

What are the goals of Topics?

Google has stated four privacy-centric aims for the development of this project:

1. it must be difficult to re-identify significant numbers of users across sites using just the API;
2. the API should provide a subset of the capabilities of third-party cookies;
3. the topics revealed by the API should be less personally sensitive about a user than what could be derived using today’s tracking methods; and
4. users should be able to understand the API, recognize what is being communicated about them, and have clear controls.

The new system makes improvements in all four of these, evident in both the process set out above and further proposed details. For example, such as basing the topics only on the hostnames. So ‘sports.example.com/tennis’ would be categorised based on ‘sports.example.com’ rather than including the extra specification of tennis.

However this is not the end of the development process. The proposal also includes a number of questions, covering factors such as how to assign topics to websites and what list of topics to use. Furthermore, as demonstrated by the movement away from FLoC 1.0 as a result of Google’s consultation processes, this is unlikely to be the last such change to occur. Although Google retains its aim to phase out third party cookies by the end of 2023, this initial announcement of the Topics API is still a way off being a complete proposal and there will still be more updates to come.

What happens now?

Google plan to launch a global developer trial of Topics in Chrome. This will enable developers and the ad industry to ‘try it out’ and engage with the user controls. Google set out that the final design and technical aspects of the user controls and how Topics works will be decided based on feedback they receive and what they learn in this trial. Google note in their FAQs that the technology is still in the early stages of development, so it may be some time before this trial launches and certainly there is no current timeframe on any final solution being available.

What should I do?

In the short term, this announcement should not change your approach to using adtech. Although the overarching principle of removing third party cookies remains clear, the exact shape of the solution adopted by the adtech world to achieve this goal remains less certain.

As with all alternative solutions to third party cookies, organisations may wish to experiment with new features to understand how they might adapt their current advertising practices in light of new technologies and approaches being developed. Topics API is another new approach that organisations may wish to add to this list.

In any event, companies should keep a careful eye on Topics as it continues to develop and evolve through feedback from both regulators and stakeholders in the adtech ecosystem as it will undoubtedly form an important part of the post-cookie solution.