As the countdown to Google’s January 2022 deadline to ax the third-party tracking cookie gets closer, buyers and sellers, and just about everyone in between them, have all been on edge.

Everyone wants to know: What will replace the third-party tracking cookie (which has outlived its usefulness) as the main tool for measurement and audience targeting?

Alternatives have been proposed to the W3C (Worldwide Web Consortium) and are currently being tested and responded to by the industry at large. Google has proposed the Privacy Sandboxa series of browser APIs that are intended to secure users’ privacy while also enabling advertising tracking and measurement—which includes Two Uncorrelated Requests, Then Locally-Executed Decision On Victory (TURTLE-DOV). (We’ll be hearing lots more about that at our upcoming webinar with Google, Building the Privacy-Forward Future of Advertising July 15 @ 2PM. Register now, it’s free.)

In May, Criteo submitted its own proposal, SPARROW (Secure Private Advertising Remotely Run On Webserver), to the W3C in response to Google’s proposal.  The proposal was updated recently, in response to industry-wide feedback, to include reporting capabilities to further secure users’ privacy without compromising advertisers’ performance.

I caught up with Charles-Henri Henault, VP of Product, Ads Platform and Analytics at Criteo to gain a deeper understanding of SPARROW. One thing that’s certain, the industry is going to need to come together on shaping the post-cookie world.

Lynne d Johnson: What is SPARROW? 

Charles-Henri Henault: In February of this year, Chrome published TURTLEDOVE (Two Uncorrelated Requests, Then Locally-Executed Decision On Victory) proposing how interest group advertising could replace user-level advertising. Criteo’s SPARROW proposal (Secure Private Advertising Remotely Run On Webserver) aims to enhance Chrome’s proposal by providing more control and transparency while maintaining privacy guarantees for users.  

These enhancements include: 

  • Audiences: Adding the ability to drive awareness or reengagement scenarios by creating more sophisticated campaigns based on interest groups (e.g. lookalike audiences).
  • Technical execution: Instead of browsers executing real-time bidding, we recommend safeguarding users’ data by having an independent party, known as a gatekeeper, execute sophisticated real-time bidding strategies. A gatekeeper could be a cloud service provider or an SSP. 
  • Measurement: Sharing of granular reporting to give more transparency into campaign management, billing, fraud prevention and brand safety while also providing more control over fraud detection, campaign optimization, and A/B testing.   

LdJ: How does SPARROW differ from TURTLEDOVE? 

CHH: We see our SPARROW proposal as an enhancement to TURTLEDOVE. In fact, SPARROW maintains many of Chrome’s objectives within their own proposal. For example: 

  • People who like ads that remind them of sites they’re interested in can choose to keep seeing those ads.
  • People who don’t like these types of ads can choose to avoid seeing them.
  • People who wonder “how the ad knew” can get a clear, accurate answer.
  • People who wish to stop being associated with an interest group can do so and can expect to stop seeing ads targeting this group.
  • Advertisers cannot learn the browsing habits of specific people, even those who have joined multiple interest groups. Websites cannot learn the interest groups of the people who visit them. 

However, we’ve also added some improvements to make sure that: 

  • Advertisers can retain campaign control and performance in privacy-friendly ways.
  • All advertising use cases are covered by the proposition, not only re-marketing.
  • Appropriate controls over ad safety, brand safety and transparency in billing is provided to both advertisers and publishers.
  • User experience is preserved while browsing the web.

Finally, we believe our proposal is key to a healthy ecosystem—one that ensures a privacy-friendly experience for users, value for advertisers and revenue for publishers. 

LdJ: How will taking the logic out of the browser help the industry? 

CHH: Taking the logic out of the browser yields the following benefits: 

  • Better user experience: Loading, storing and running all the components and logic in-browser would put a huge strain on the user experience.
  • Better marketing: Campaigns would be executed on web servers with computing power vs. mobile-based browsers. SPARROW also allows for A/B testing, helping to improve marketing effectiveness, as well as better user engagement by delivering enhanced creatives that do not have to be stored in the browser. This lifts the constraint on their quality and allows for higher publisher monetization.
  • Enhanced advertiser protection: An in-browser execution could, to a certain extent, allow Advertiser A to have access to Advertiser’s B strategy, and potentially even reverse-engineer its proprietary marketing approach. SPARROW ensures that the interests of Advertisers A and B are not at risk when engaging with online audiences.
  • Improved spend auditability and budget management: Both the browser and the gatekeeper would have visibility on display volumes and prices and real-time spend reporting would be made available.  

We believe SPARROW still has room to address other topics, though, such as post-view reporting, multi-touch attribution, reach counting and fraud management.  

LdJ: How will the inclusion of a ‘gatekeeper’ broaden targeting and speed up reporting? 

CHH: SPARROW provides the system the ability to build elaborate and relevant audiences by building new interest group categories based on matching other interest groups together. 

By allowing a regular flow of information between browsers and gatekeepers, SPARROW enables fast reporting and precise management of budgets. In comparison, the in-browser logic shared in TURTLEDOVE only allowed for aggregated and delayed reporting.  

LdJ: Would publishers have to change much of what they already do to implement SPARROW? 

CHH: Publishers would not need to change much in that they would still send bid requests to web servers and get bid responses in exchange. SPARROW offers them the opportunity to create their own audience segments. 

LdJ:  There were some questions being raised in the industry about whether SPARROW meets privacy standards. Does the updated proposal now meet privacy standards? 

CHH: We believe SPARROW provides similar levels of privacy as TURTLEDOVE, in the design space set forth by Google Chrome teams whereby users are addressed by their membership to cohorts. 

LdJ: How does the SPARROW proposal tackle transparency, which is one of the biggest issues within the ecosystem right now?  

CHH: Transparency is incredibly important to marketers. Thanks to constructive industry-wide feedback, we recently updated SPARROW’s reporting capabilities in GitHub the other week to further secure users’ privacy without compromising advertisers’ performance.  

The SPARROW update introduces three new reports: 

  • A low latency aggregated report, whose purpose is to be used for campaign spend management and billing
  • A delayed, personalized, display-level report, defined by the user, with privacy-preserving mechanisms, intended to be used for fraud detection, campaign optimization (machine learning), AB testing, etc.
  • A delayed report listing all ad units served (without counting them precisely), for publishers to be able to audit publisher brand safety. 

LdJ: Is SPARROW more theory than real-world framework? 

CHH: The gatekeepers make the entire proposal realistically implementable and would not threaten the user experience browsing the web. Google recently acknowledged the seriousness of our proposal, proposing that SPARROW and TURTLEDOVE move forward along the track toward becoming a standard. Further discussion with the other browser vendors should ensue.  

It’s important to note that we see SPARROW as a continuous work in progress. We designed it to help kickstart ideas in the industry and propel the industry forward. Regardless of which proposal ends up being adopted, we strongly believe the entire industry needs to work together to find a solution, one that respects the end user’s privacy and gives them control or choice over their data. 

LdJ: Can you elaborate on the gatekeeper concept? How do you have a gatekeeper who is independent, unbiased and not self-serving? 

CHH: The gatekeeper is designed to act as an independent third-party between the publisher and the advertiser. It is essential that there is no coordination between the gatekeeper and other parties in the ad tech ecosystem. Gatekeepers would manage a lot of traffic and run the engines built by the advertiser. Thus, running a gatekeeper would be quite compute-intensive and quite low-tech at the same time. A lot of details remain to be clarified, but we think that cloud providers or current SSPs could be interested in stepping in.  

LdJ: How can we maintain privacy protection for users in this proposed ecosystem? 

CHH: At Criteo, we’re committed to maintaining privacy protection for users. All of our solutions are privacy-by-design and operate strictly under user consent. One way we can continue to maintain privacy protection in the SPARROW proposal is by de-coupling advertiser-side user activity and publisher-side one. This will ensure that any participant has limited information about users while still enabling them to serve relevant ads.

Don’t forget to sign up for our free webinar with Google Building the Privacy-Forward Future of Advertising to learn how you can actively participate in the construction of the next generation of solutions.

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