Interest-Based Advertising: What a Positive Post-Cookie Test from Google Signifies

In April 2023, Google released the results of a test that compared the results of privacy-friendly interest-based advertising with advertising that leaned on endangered third-party cookies.

The results didn’t blow the doors off – scale, clicks, and approximate ROI from the privacy-first solutions lagged only slightly behind third-party results – but they did show evidence of a privacy-forward path to performance.

Tech Specs of Google Ads' Interest-Based Advertising Testing

First, the test specs: it was conducted across Google Ads, Display, and Video 360 with a sample of publishers and advertisers in Europe over a six-month period. It involved two groups: one with IBA restrictions enabled and one without. The former group is in line with Europe’s GDPR privacy law, which may well become a privacy standard across other areas of the globe. 

What the Results of Interest-Based Advertising Testing Mean

Now for the significance: while performance didn’t exactly match that of the cookie-based campaigns, the close approximation shows that Google’s targeting algorithms have improved enough to make interest-based audience targeting a viable option for advertisers going forward. An added but somewhat predictable wrinkle in the test: AI-powered optimization options including Maximize Conversions brought the IBA campaign performance even closer to cookie-based campaigns. 

It’s easy enough to read the tea leaves and see that this is where Google advertising is headed. Our recommendations are to find ways to train Google’s algorithms by improving signal data (e.g. optimizing to lower-funnel / higher-value conversions by integrating CRM data) and understanding all your options on a dwindling set of levers in the Google Ads UI. And keep an eye out for future results from similar tests Google is running in the UK, which will provide indicators of the platform’s direction in the near future.

If you have any questions about how to wrangle Google’s algorithms in your marketing strategy, drop us a line!