One of the leading alternatives comes from Google. With its ‘Privacy Sandbox’, Google seeks to help develop as many different approaches as possible. The results should then lead to open standards. For this reason, the World Wide Web Consortium (W3C) is involved in the project.
The list of ideas is long and contains vastly different concepts for various fields of application. The biggest challenge faced by the Privacy Sandbox: It takes a lot of time to develop a universally recognised standard. There are also several drawbacks, like with the FLoC model (Federated Learning of Cohorts). This model was the first choice for a while, but was ultimately rejected by too many data protection bodies and browser developments.
The Topics API provides one example of this. The idea behind this API is to enable ads to be aligned to user interests while simultaneously protecting their privacy. The concept: A website assigns its content to generic lists of topics like ‘Football’ or ‘Entertainment’. The user’s browser then determines which 5 topics the user is most interested in at present. Users can view and modify this list, or opt out of participating in the Topics API.
The FLEDGE API (First Locally-Executed Decision over Groups Experiment)
takes another approach. In this case, the idea is to move the bidding process for ad space from numerous online servers to the browser itself. Ad customers should still be able to reach certain user groups. Retargeting and frequency capping would likewise be possible. Ultimately, ads should only be transmitted by trustworthy servers.
As things currently stand, it remains to be seen which ideas will succeed and
what they will achieve in practice.