Updates on Privacy Sandbox Tests

This month started with very intersting news in the industry:

Reports on Google Privacy Sandbox

1. Criteo

Criteo did a very in-depth study about Google Privacy Sandbox and I was trying to write a good report with the main takeways, but Marketecture beat me to it. Go read both reports if  you want to learn more about it.

In a nutshell, the Privacy Sandbox from Google is a set of tool from the browser to protect people's privacy while browsing the open web. From Google's website, it has two main goals:

  • Phase out support for third-party cookies when new solutions are in place.
  • Reduce cross-site and cross-app tracking while helping to keep online content and services free for all.

To do so, Google is developing a lot of internal parts within the browser, with the focus to preserve good targeting & measurement capabilities after cookies go away.

Now, Google participates in all the technical ecosystem, from publisher to advertiser, and they have a very big market share in terms of browsers (~60% according to wikipedia), so their solution has a strong impact on how each player monetize the dollars spent by brands in advertising.

Initial results from Criteo shows, if third-party cookies were deprecated today and the Privacy Sandbox released in its current state:

  • Publisher revenues to decrease by an average of 60%
  • Increase of more than 100% latency in publisher ad rendering on Privacy Sandbox traffic
  • Disproportionate market share gain by GAM -  significant increase in publisher reliance on Google for ad revenue
We believe the Privacy Sandbox has the potential to be a sustainable alternative to third-party cookies, provided our requests are satisfied, a disciplined rollout schedule is maintained, and a clear roadmap is provided. We are committed to continue helping Google close Privacy Sandbox gaps through our partnership and testing. 

2. Index Exchange

The second Privacy Sandbox test result was published from Index Exchange

They've been testing the Protected Audience (PA) and Topics API since Chrome disabled 1% of the third-party cookies in January 2024.

Their findings so far:

  • Overall available impressions and spend is limited, which makes testing hard
  • They see some topics getting a big volume, obviously you see the usual here: sports, news, games/computer/videogames, arts & entertainment and whatnot.
  • And they saw a decline in CPMs, which will hurt publisher's revenue.


Overall, it seems the Privacy Sanbox is a massive shift on the way programmatic advertising works today

Remember that there are lot's of steps and tech involved in rendernig an ad, as you can see in my diagram below. All this might change with Privacy Sandbox (like moving the auction to the device in a protected environment).


We are already in half of 2024, so let's see how the industry evolves.

Test cookie-less alternatives!

Navigating the Changing Landscape of AdTech: The Importance of Choosing the Right Tech Partners