Even clean rooms have to play in Google’s Privacy Sandbox.
Optable, which operates a data management platform (DMP) and a clean room, announced its early access program for Chrome Privacy Sandbox activation on Thursday. Through the program, advertisers can target audiences for Privacy Sandbox auctions by matching their data graphs to those of publishers that are integrated with Optable.
Although Optable participated in the W3C Privacy Sandbox working groups and has been testing Sandbox API integrations for the past eight months, this program represents its first foray into running real campaigns, said Chief Product Officer Bosko Milekic.
What do you mean, “early access”?
It’s pretty wild that any Privacy Sandbox solution launching in 2024 could be described as “early access.”
After all, Google has been expanding availability of Sandbox APIs for testing since July, and the APIs were generally available for all Chrome users as of September.
But that doesn’t mean the APIs have been ready to support real campaigns. In fact, the amount of available supply for Sandbox campaigns remains low, Milekic said.
That’s because Google Ad Manager (GAM) decides when to actually trigger a Protected Audience auction instead of defaulting to its traditional auction flow (i.e., accepting bids from SSPs submitted through Prebid.js and weighing those bids against direct-sold GAM line items and Google Ad Exchange bids). And, “from what we’re able to tell, it’s not happening very often,” he said.
As of now, GAM runs an on-device Protected Audience auction when the user is in Chrome’s 1% cookieless pool and the publisher is using GAM’s programmatic demand. Because GAM functions as an SSP and seller, it asks buyers that submit bids through its exchange (either via Authorized Buyers, Google Ads or Display & Video 360) if they would like to participate in a Protected Audience auction on each eligible bid request.
GAM can also run a Protected Audience auction if at least one of the publisher’s SSPs or authorized sellers submits a request for one, although this is not a requirement.
A small subset of cookied users that amounts to about 5% of Chrome traffic is also sometimes eligible for Protected Audience auctions. (This document explains how GAM’s logic works. Impressions in the Mode A group that receive label_only_2, label_only_3 and label_only_4 designation sometimes trigger Protected Audience auctions. In some cases, GAM also runs Protected Audience auctions on non-labeled traffic, according to a Google spokesperson.)
Still, the vast majority of Chrome traffic is not currently eligible for Protected Audience auctions.
Google has said it expects as much as 10% of Chrome impressions to be eligible for Protected Audience auctions as of the beginning of this year. But Optable says, based on what it has observed so far, GAM is triggering Protected Audience auctions on only a single-digit percentage of impressions.
However, Optable expects, as cookie deprecation ramps up from 1% of Chrome users to 100% by the end of the year, the frequency at which GAM triggers Protected Audience auctions will also ramp up, Milekic said.
So Optable is launching this program now to get a handle on how these auctions will work in practice to prepare itself for when most Chrome campaigns are using the Sandbox APIs.
How it works
To enable Sandbox campaigns, Optable integrated Chrome’s Protected Audiences API for targeting and its Attribution API for measurement.
Advertisers can build targetable audiences within Optable’s platform using their first-party data in its DMP or audience matches derived within its clean room. Advertisers can then use their first-party data to inform their bidding rules. (For example, a brand might have data on the best times to reach its customers, and it can adjust bids accordingly.)
Typically, Optable models audiences by using deterministic data like email addresses or phone numbers to find matches within its clean room. But for Privacy Sandbox campaigns, it can also include anonymous users from Chrome’s Protected Audience cohorts.
Optable can sell ad inventory on behalf of publishers that have integrated its SDKs into their on-page code. These integrations allow Optable to function as what the Protected Audience API calls a “component seller,” enabling it to process demand for Protected Audience auctions on behalf of the publisher.
A publisher can also designate Optable as a buyer, which allows advertisers to use the publisher’s first-party data to target members of that publisher’s audience on other sites. This way, publishers can participate in audience extension campaigns without needing to join an audience network.
And because Optable is integrating with SSPs as a Protected Audience demand source, it’s able to bid on publisher inventory without relying on traditional real-time-bidding integrations with DSPs.
Measurement concerns
In addition to building audiences, the early access program will allow advertisers to measure their campaign performance.
By integrating the Attribution API, Optable can assign conversions to ad impressions without needing to use third-party cookies. The Attribution API aggregates conversion data, which, by design, makes it harder to tie conversions to specific users.
The Sandbox differs from legacy measurement solutions in that it doesn’t require an advertiser or its tech partners to use a unique user ID to tie conversion events to ad impressions.
“The more data with personal identifiers that’s generated and sent out into the ether, the more risk to the end user when that data gets compromised,” Milekic said.
The Sandbox’s measurement approach is less prone to data leakage, but more testing needs to be done to determine how accurate it is.
What to watch
Now that it’s enabled real campaigns to run through the Sandbox, Optable will be assessing how targeting and auction dynamics work under real-world conditions, in addition to pressure testing measurement capabilities.
One way the Privacy Sandbox already differs from existing targeting methods is that a provider like Optable doesn’t need to use a DSP to target a Protected Audience, Milekic said. The ability to create and target audiences derived from Chrome’s anonymized user cohorts is baked into the platform.
Meanwhile, DSPs have to adapt their usual methods of creating audiences to the Privacy Sandbox’s framework, which is a heavy lift, Milekic said. In contrast, Optable can create new audiences directly within its own platform, without relying on how it’s worked with DSPs in the past.
However, Optable still needs DSP integrations to build audiences for non-Sandbox campaigns, Milekic added.
For now, the vast majority of campaigns are not running through the Sandbox. But Optable is keeping an eye on the rate at which Google Ad Manager triggers Protected Audience auctions and how that rate is affected by how much Protected Audience demand Optable sends to a publisher, Milekic said.
Milekic is optimistic the Privacy Sandbox will eventually be a boon to publishers looking for new demand sources and advertisers hungry for greater audience scale.
But it’s too soon to know how everything will work once Chrome disables third-party cookies for all users, he said. “So I couldn’t be more excited to see the scale ramp up as fast as possible.”
Update 1/31/24: A Google spokesperson clarified how GAM triggers Protected Audience auctions and when it decides to do so.
