The ad tech identity catch-up: Topics API, Protected Audience API, and Unified ID 2.0

It’s one of the subjects on everyone’s minds: the climate of curiosity and suspense as the ad industry leans into the future of programmatic advertising in a post- third-party cookie world.

In the last few months, we’ve delved into the questions surrounding whether contextual ads can replace third-party data and the impact of state privacy laws on the future of the industry.

We’ve spent time documenting the news concerning some of the topics on the tip of the ecosystem’s collective tongue: Topics API, Protected Audience API (previously known as FLEDGE), and Unified ID 2.0. In this article, we’ve paired a comprehensive selection of news with a micro history of the solutions. 

[Need a crash course in the history of the deprecation of the third-party cookie? We created a handy guide that takes you from January 2020 through last year.]

Now, let’s dive into our identity solutions news round-up.

Topics API

What is Topics API?

Topics API is an identification that focuses on topics of interest to the user. It utilizes in-browser machine learning, allowing the browser to select three topics to create a comprehensive map of user interests based on browsing activity.

This process plays out across participating websites over a period of three weeks, after which the topics are deleted and replaced with fresh ones.

A few things about this are geared to maximizing user privacy and minimizing targeting. The deletion process, of course, is paramount. But so is the fact that the topics come from a central 469-item topics taxonomy, which has items that range from “comics” to “law and government”.

This taxonomy means that users’ interests are determined from a pre-existing selection rather than, for example, grouped into a cohort based on their habits—which is how FloC, Google’s earlier alternative to third-party cookies, operated.

What’s new with Topics API?

One of the most important news items concerning Topics API is that it’s here. Well, it’s generally here—it became widely available with Chrome’s July 12th update.

“Google will make the targeting and measurement APIs in its Chrome Privacy Sandbox generally available for all users in July so developers can do scaled testing before the phaseout of third-party cookies begins next year, as planned,” writes Allison Schiff in AdExchanger.

Google’s Privacy Sandbox updates have been met with what Digiday termed “skepticism and a little more optimism,” with concerns raised leading to the eventual pushing back of the third-party phaseout.

Despite enhancements and updates to the Topics API—including an improved topics taxonomy, per-caller filtering, user controls, and speed improvements—a few eyebrows remained raised about the API. Kevin Joyner, director of data strategy at digital agency Croud, commented that it’s not “100% watertight privacy protecting.” (Source)

Protected Audience API

What is Protected Audience API?

On April 17th, it was announced that FLEDGE was being renamed to Protected Audience API.

After all, FLEDGE was an acronym for First Locally-Executed Decision over Groups Experiment—and, by spring of this year, it was decided that the experiment phase was well and truly over.

The idea behind the Protected Audience API, another prominent castle in the Privacy Sandbox, was to preserve user privacy via consolidating information. “Users are often trailed by hundreds of third-party cookies, and tracking is completely decentralized. The idea behind [the Protected Audience API] is to protect user privacy by centralizing that power.” (Source)

The advertising is interest group based, and the ads shown to the user are chosen by the browser, based on which sites the user visited before. Data security is ensured through on-site auctions. 

So, how is Protected Audience API different from Topics API? With Topics API, you can access predetermined user groups whereas Protected Audience API gives more control to target custom audiences. “Put simply, Topics is a less complex version of [the Protected Audience API].”

What’s new with Protected Audience API?

The Protected Audience API is also becoming available to all users in July.

Along with Topics API, both APIs are going to be viewed through a strong lens and examined by many eyes searching for issues and problem areas. A few of these include “whether antitrust concerns will be fully addressed and whether the APIs will be as effective as what they’re replacing.” (Source)

And, because Google maintains that it’s sticking to its 2024 deadline on phasing out third-party cookies, there’s only about a year to test and examine what the Privacy Sandbox has to offer.

Unified ID 2.0

What is Unified ID 2.0?

The Unified ID 2.0 uses the identifier of anonymized email addresses as a replacement for third-party cookies. In a previous post on various ID solutions, we examined what made Unified ID 2.0 unique. With so many alternatives being developed in parallel, the jury’s still out on which solution will end up becoming the gold standard, however UID 2.0 is one of the frontrunners in the ID race.

Earlier in 2023, Jeff Green, CEO of The Trade Desk, commented that UID 2.0 “solves the needle-in-the-haystack problem that came with cookies” and “advertisers can now match their customer data with accuracy across the open internet more effectively than ever before.”

But, as has been noted in trade publications, there are questions—and news updates—surrounding this identity solution. 

What’s new with Unified ID 2.0?

In 2022, Prebid, which was slated to serve as the public operator for UID 2.0, hit the pause button on assuming that role. In fact, there’s been speculation that having multiple private operators—including AWS—is a more likely future for UID 2.0 than having a public operator overseeing everything.

And, even though that could “slow down adoption,” according to AdExchanger, Kanishk Prasad, a senior product manager at The Trade Desk, suggests that the private operator option is better for UID 2.0’s prospects in the long run. What’s the reason for this?

“It’s very important for us to be able to appease the security concerns people have about sending out their user data,” Prasad said. “For that reason, I’d argue that the private operator concept has helped people get more comfortable and actually helped us accelerate.”

Is this acceleration happening? Certainly: several large platforms have recently incorporated UID 2.0. But there are also a number of questions being raised about the use of email addresses.

One pressing concern is the efficacy of UID 2.0 when many people use temporary or throwaway email addresses when they browse; another is the prevalence of machine-generated email. (Source

What’s next? 

The next year is set to be an eventful one, with the clock ticking on the phaseout of third-party cookies, and possible identity solutions still being checked for flaws and weaknesses.

We’re keeping an eye on the news and will continue to discuss the updates as they come—both around the water cooler and on the Blockthrough blog.

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