A NEW STUDY EXPOSES A HIDDEN FLAW IN A-B TESTING ON DIGITAL AD PLATFORMS

Summary from the TLDR Marketing newsletter

A new study shows that A-B testing on platforms like Meta and Google may produce misleading results due to "divergent delivery", where targeting algorithms assign different ads to distinct user groups. These algorithms optimize ad targeting based on relevance to users, meaning the “winning” ad may perform better simply because it was shown to users more likely to engage, rather than due to superior creative content. This inherent flaw in the testing process compromises marketers' ability to draw accurate conclusions about ad effectiveness.