In plain English: What do Google’s Privacy Sandbox proposals actually mean?

By Georgie Haig, product lead, MiQ

A blog series explaining some of the concepts, processes and technologies we need to do our jobs – in plain English.

Google’s Privacy Sandbox are a set of proposals for the future of web advertising with the lofty mission to “create a thriving web ecosystem that is respectful of users and private by default”. But if anyone can aim for this kind of lofty goal, it’s Google. 

Firstly, what are the Privacy Sandbox proposals? Essentially, it covers solutions in key areas of programmatic, to allow them to continue to operate in a world beyond cookies:

  • Interest-based targeting, enabled by a solution called FLoC
  • Retargeting, via a solution called Turtledove (and its newest iteration, Fledge) 
  • Conversion measurement – beyond just basic post-click functionality
  • A range of other privacy preserving proposals, including limiting the number of identifiers (eg IP address, browser user agent) that can be shared for identity workarounds.

Here’s what all of that means in practice.

Decoding the latest Chrome updates

It’s just over a year since the Chrome team announced plans to phase out third-party cookies. The latest announcement provides an update and some clarity around their plans for post-cookie advertising functionality, including: 

  1. Federated Learning of Cohorts (FLoC)

Chrome is doubling down on FLoC as a solution for targeting users based on what they’re interested in rather than with cookies. FLoC is designed so a user’s own browser groups them into ‘cohorts’ of users with similar browsing habits. Only the cohort ID is made available to the ad tech ecosystem for targeting, so you can’t see an individual user’s identity and/or do any microtargeting. 

While their intentions are good, the FLoC proposal hasn’t been received all that well within the industry until now because:

  • If it’s Google (or any browser) deciding what a group looks like, you’re removing marketers from a pretty crucial step.
  • And the initial results from Google’s own whitepaper weren’t all that compelling. (They essentially showed better performance than broad reach, as measured by Google itself).

But with Google seeming to double down on this solution, the rest of the industry may have no choice but to re-evaluate its use as a part of prospecting strategies for reaching people browsing Chrome.

  1. Turtledove and Fledge

Turtledove is the Privacy Sandbox proposal that aims to replicate retargeting without cookies, in a similar way to FLoC by building intent-based groups whose identity is kept private within the browser. The latest announcement, Fledge, appears to be a response to industry feedback about the need for a ‘trusted third-party’ to control the ad auction itself, and more flexibility in who builds first-party audience segments. From the looks of things, we’ll be able to test Fledge out soon, so watch this space. 

  1. The prototype for IP masking

The Chrome team seem determined to address user ‘fingerprinting’ – using a combination of identity signals to create a stable ID for microtargeting –  through IP and User Agent masking. ‘Gnatcatcher’ is their new proposal for IP masking that routes web traffic through a ‘privatizing server’, to hide individual IPs while still allowing basic website functionality that relies on IPs. 

What does this mean right now?

To be honest, not much as yet. The updates from Chrome are extremely welcome in terms of seeing their thinking and the direction of travel. But what they really show is that the world beyond cookies is still pretty unclear. 

For companies like ours, it’s a question of continuing to test Privacy Sandbox functions as they’re made available and making our feedback heard along with the rest of our industry. 

For advertisers, it’s a case of continuing to stay on top of what new identity solutions are in development and, as our founder Gurman Hundal said in a recent Adweek article, getting their first-party data in order so they can explore the benefits of data bunkers.