Now that Chrome’s cookie deprecation has been delayed until early 2025, there’s more time for testing ad targeting alternatives.

Google Chrome’s Privacy Sandbox is one of the options being tested, with MiQ (an independent global programmatic and marketing intelligence company) trialling the solution’s Attribution Reporting API (ARA) and releasing results of early testing of the ARA’s event-level reporting.

Event-level reports associate individual ad clicks and views with attributed conversion events, while summary reports provide aggregated conversion data for a more complete view of performance, including more detail about results such as cart contents and the monetary value of conversions.

“The Google Privacy Sandbox Attribution Reporting API is designed to help advertisers measure the effectiveness of their ad campaigns while preserving user privacy,” says MIQ chief commercial strategy officer John Goulding. “It allows advertisers to track conversions such as purchases or sign-ups resulting from their ad campaigns. It aggregates data across users to provide insights without revealing individual user actions.”

Goulding tells MiC that, so far, ARA is performing better than anticipated. In the first wave of testing, ARA reported on 84.9% of the same unique converters as cookies, with an additional 3.7% that cookies did not capture.

On the downside, Goulding says ARA lacks a complete measurement dataset. ARA event-level reports show a high percentage of Chrome converters but, on a campaign running across multiple browsers and devices, it shows a lower percentage of total conversions than cookies. That’s a problem since fewer conversions means lower ROI.

Goulding says that ARA data is usable for measurement, but modeling will be required in order to accurately represent the true ROI of campaigns. “Given the prevalence of modeled conversions within tools such as Campaign Manager 360, this doesn’t feel like a blocker to ARA’s adoption; ultimately a combination of summary and event-level reports will likely be needed in order to most accurately model out true campaign performance.”

MiQ believes ARA is one of many solutions that can be used in combination to deliver the best campaign outcomes.

“It’s absolutely not an apples-to-apples direct replacement for cookies,” says Goulding. “I think this is the main thing that companies need to wrap their heads around, which is that it’s not going to work exactly the same and there are trade-offs as we increase user privacy. But companies can work through that and make it work successfully regardless.”