I haven’t looked into the technicals much further than the support page.

The way i read it, it sounds like the companies will get some general data if their ads work without a profile about you being created. I would be fine with that. What I don’t like is the lack of communication to users about it being enabled.

PPA does not involve websites tracking you. Instead, your browser is in control. This means strong privacy safeguards, including the option to not participate.

Privacy-preserving attribution works as follows:

1. Websites that show you ads can ask Firefox to remember these ads. When this happens, Firefox stores an “impression” which contains a little bit of information about the ad, including a destination website.
2. If you visit the destination website and do something that the website considers to be important enough to count (a “conversion”), that website can ask Firefox to generate a report. The destination website specifies what ads it is interested in.
3. Firefox creates a report based on what the website asks, but does not give the result to the website. Instead, Firefox encrypts the report and anonymously submits it using the Distributed Aggregation Protocol (DAP) to an “aggregation service”.
4. Your results are combined with many similar reports by the aggregation service. The destination website periodically receives a summary of the reports. The summary includes noise that provides differential privacy.

This approach has a lot of advantages over legacy attribution methods, which involve many companies learning a lot about what you do online.

PPA does not involve sending information about your browsing activities to anyone. This includes Mozilla and our DAP partner (ISRG). Advertisers only receive aggregate information that answers basic questions about the effectiveness of their advertising.

This all gets very technical, but we have additional reading for anyone interested in the details about how this works, like our announcement from February 2022 and this technical explainer.