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Just hours before Google announced its U-turn on nixing third-party cookies, Amazon emailed publishers asking them to join its program adopting a key part of Google’s replacement of cookies: Privacy Sandbox. Now, the ecommerce giant has walked back that push, confirming to ADWEEK that it no longer plans to proceed with the cookieless ad offering—another setback for the industry’s sputtering shift toward a privacy-centric future.
According to screenshots of emails to two publisher sources from Amazon, dated before Google’s cookie announcement on April 22, Amazon Publisher Services planned to widely launch an API that supports Google’s Protected Audience API (PAAPI)—a retargeting tool within Privacy Sandbox that moves ad auctions from the ad server to the browser.
In a world without cookies, Google touted PAAPI as a way to help marketers retarget people in Chrome by assigning them into interest groups. These signals are then shared from the browser as part of the request to enable the demand-side platform to show relevant ads. For instance, someone who has previously visited Nike.com could be put into the “running shoes” interest group (or IG) and shown ads for running shoes.
“APS is launching a new API that supports Google’s Protected Audience API (PAAPI), creating an additional path to monetize anonymous users starting in Q2 2025,” one email read. Amazon had planned a phased rollout in the U.S. beginning May 19, according to the same email.
An APS spokesperson told ADWEEK that based on Google’s recent announcement, the company is no longer “integrating” this API at this time, meaning that it is no longer retooling its demand-side platform to receive PAAPI signals from the browser. APS had been testing this PAAPI program with select publishers since at least April 2024, according to one of the emails. The spokesperson claimed that publishers will see no effect because the API was in the early phases of testing.
“Amazon Ads has invented advanced technology to help publishers serve ads to relevant audiences without third-party cookies, including Ad Relevance, Amazon Publisher Cloud, and Signal IQ to name just a few,” said the spokesperson. “We also continually explore third-party capabilities that publishers can easily integrate through Amazon Publisher Services Connections Marketplace.”
The fate and future of Google’s Privacy Sandbox APIs is in flux as the Google team gathers industry feedback to inform an updated roadmap.
Adtech companies, publishers, and advertisers have invested time and millions of dollars in engineering and testing Google’s cookieless technology over the last five years. Marketers have increasingly been voicing their frustration.
If Amazon’s DSP—used by two in three U.S. advertisers, according to a survey by Advertiser Perceptions—continued to integrate PAAPI and receive these signals from the browser, then that could have served as a lifeline to that specific piece of Privacy Sandbox tech.
PAAPI, however, has not been particularly popular and its critics have said that it has lacked transparency.
PAAPI had seen slow momentum
Following Google’s U-turn, the information from PAAPI interest signals can be found in cookies, so advertisers can continue to buy cookie-based inventory. Amazon no longer needs to re-tool its adtech towards receiving signals from the browser.
Google said that up to 10% of Chrome traffic is enabled for PAAPI testing. But one publisher who had been testing Amazon’s PAAPI program since last year said that they saw slow momentum.
“We started the conversation [with Amazon] in April [2024], and really began testing in November,” said the first publisher source, who spoke on the condition of anonymity. “But the Amazon DSP struggled to spend against the signal—that was the biggest roadblock.”
In other words, advertisers were not activating against these signals, according to this publisher. This might not be unusual, given the whole host of cookie alternatives jostling for ad spend, and the remaining existence of third-party cookies.
But it’s also unlikely that any more marketing goals will be set against this signal, so no exclusive budgets will be spent via PAAPI through Amazon DSP, noted the first publisher source. One of the two emails viewed by ADWEEK touted that being part of Amazon’s program would give publishers access to budgets focussed on testing PAAPI.
This publisher, who had planned to continue investing in Privacy Sandbox despite Google’s U-turn, said they hadn’t been informed by Amazon about pausing the rollout at time of writing.
At time of writing, a second publisher, speaking on condition of anonymity, recently met with Amazon’s team at Possible in Miami, but had also not been informed by Amazon of its reversal.
Amazon did not respond to specific questions about whether its DSP struggled to spend against the signal.
