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What Is Google FLEDGE and Why Is It Important for Your Business?

Wilson Lau

Sr. SEO Marketing Manager @ AdRoll

For anyone in the digital marketing space, the removal of third-party cookies has been a critical moment in the evolution of consumer privacy and advertising strategies. When Google announced its decision to begin phasing out third-party tracking cookies from its Chrome web browser in January 2020, marketers everywhere began scrambling to find alternative solutions that would allow for behavior and interest tracking across the web without infringing on customers’ privacy rights. With the timeline for the end of third-party cookies now set for 2023, Google is stepping forward with potential solutions that could help marketers reach customers in what they’ve called a “more privacy-first web.”

The totality of those proposed solutions is called Google’s Privacy Sandbox. The Sandbox has so far generated a range of proposals from ad tech creators, developers, agencies, and other stakeholders in the marketing world. So far, two solutions have dominated the conversation: FLoC and Google FLEDGE.

FLEDGE is the next step forward in helping marketers and brands find alternative ways of tracking consumer behavior for advertising purposes. This article will briefly introduce Google’s Privacy Sandbox, define Google FLEDGE, and explain why it will be an essential tool for brands in the future.

What Is the Privacy Sandbox?

The Privacy Sandbox is an open-source collaboration between Google, ad tech engineers, developers, privacy experts, and marketers created to find effective tracking solutions to replace the third-party cookie and help the worldwide web evolve into a more privacy-oriented space for consumers. Customer privacy and control over data have become a hot-button topic for both consumers and advertisers — brands increasingly need to comply with new data laws that attempt to ensure customer privacy. 

Within the Privacy Sandbox, participants are developing new technologies to improve privacy standards and provide advertisers with the tools they need to engage users with personalized content. 

What Is Google FLEDGE?

One of the most complete solutions yet proposed through the Privacy Sandbox project, FLEDGE is the first real tool available that claims to let advertisers deliver ads while respecting the modern era’s new standards around privacy. It operates on three main principles established within Google’s TURTLEDOVE proposal, which seeks to set standards for data sharing:

  • Browsers may hold users’ behavioral data

  • Advertisers can use this data but cannot combine it with other data collected while delivering ads to the user

  • Ad networks may not store users’ interest data

This framework strives to make it possible to market to groups separated by interest without infringing on privacy rules.

So, what is Google FLEDGE? It’s a proposal for a workflow (using FLoC API technologies) that will help marketers connect with relevant user groups and deliver personalized ad content. FLEDGE stands for “First Locally Executed Decisions over Groups Experiment.” It consists of five primary steps executed by browsers, buyers, and sellers.

1. Browsers record interest groups

At its core, FLEDGE is about letting publishers, advertisers, and ad tech companies assign (anonymous) users to specific interest groups. Browsing behavior and activity define these interest groups. Publishers or advertisers can own interest groups.

In FLEDGE, owners of interest groups are empowered to add users to groups based on their behavior by calling a Javascript function, “joinAdInterest Group().” The interest group owner passes all information, including ads and the name of the interest group, to entities who will participate in an auction for the ad space for that interest group.

Note that users’ browsers can only be placed in an interest group for 30 days to protect privacy, after which the Javascript call must be made again.

2. Sellers run on-device auctions

Next in Google FLEDGE, the seller activates an API function inside the browser on the publisher’s page. The browser will then automatically execute smaller workflows for the buyer and seller. Under the FLEDGE logic, sellers will use Javascript to define parameters for bid prices and metadata, determining the results and winners of each auction. The seller decides who can bid on ads and records auction outcomes and final prices.

3. Buyers execute on-device bids

Buyers (those seeking the ability to publish ads — could be a brand, a publisher, or an ad tech provider) decide which auctions to participate in. At this point, the buyer will define the ad itself and enter it into the auction platform along with metadata and a price. Buyers and sellers will be able to define their own needs for metadata with each ad. 

4. Browser renders ads

When the seller entity has declared a winner for the auction, the winning buyer (who could be a publisher or the owner of an interest group) transmits the ad information — including metadata and creative — to the browser, which renders the ad inside a protected area the Google FLEDGE project calls a Fenced Frame.

The idea behind the Fenced Frame is that it’s a secure area within a greater webpage that does not share user data with the rest of the web page. This prevents brands and web hosts from collecting user data on the web page and combining it with browser data, which would infringe on user privacy. However, the technology to make Fenced Frames possible is still under development. 

5. Event-level reporting

With the auction complete and the ad successfully displayed and served to the relevant user within an interest group, participants (including the seller, buyer and browser) can record outcome data from the auction. This will help buyers craft better ads and more cost-effective bids for the opportunity to engage with users. Bidders who did not win the auction can also access this data in order to improve their bidding strategies in the future.

To Wrap Up

Google FLEDGE is still being developed and refined by the stakeholders in the Privacy Sandbox, and there will likely be much more information coming down the pike both from Google and from entities making use of the solution. FLEDGE will be available on a trial basis through Chrome in 2022, and real-world data will help its creators improve the workflow to better suit the needs of advertisers and publishers while protecting user privacy.

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