Topics API

In this Media Review, you can read about Privacy Sandbox’s General Availability, rebranding of First-Party Sets and enlarging its scale, further obstacles in the way of tracking individual users across the Internet, and regulatory updates in Europe.

It might have been delayed, but the end of third-party tracking cookies is coming at the beginning of 2025, and businesses can’t afford to keep pretending otherwise. The good news is that thanks to this delay, there is still a small window of opportunity for companies to prepare for the cookieless future by engaging with the Google Chrome Privacy Sandbox.

Have you heard of Seller-Defined Audiences (SDA) yet? SDA was released at the beginning of 2022 by Project Rearc – an initiative that came to life as the IAB Tech Lab’s answer to the impending demise of 3rd-party cookies. Although a year hasn’t passed since its release, SDA has received significant attention in the press and industry conferences and is considered one of the go-to solutions for targeting when the 3rd-party cookie pond dries up.

On April 18th, Google published the results from Google Ads’ interest-based advertising testing, where, among other tools, Topics API was analyzed. We are happy that the Google Ads team joined RTB House and Criteo in openly publishing findings from experiments with Privacy Sandbox APIs.

In the report, the Google Ads team compares the effectiveness of applying Topics API, contextual signals, and publisher first-party IDs instead of cookies for Interest-Based Advertising (IBA). Third-party cookies were allowed in this experiment for use cases unrelated to targeting, such as frequency capping and measurement.

The cookieless future is fast approaching. This decision by Google, sparked by very real privacy concerns, removes a key personalization capability for advertisers: third-party cookies. To counteract this, Google has been building a series of tools to replicate their functionality, and today we’re going to dive into one of them: Google Topics API.

Topics API has been discussed many times in the media at a conceptual level, but there are few detailed studies, especially showing the scale of availability of these signals in the browser. We will try to answer the question of what causes this.