Privacy Settings and Ad Perception: The Shift from Third-Party Cookies to the Privacy Sandbox

Online behavioral advertising, heavily reliant on privacy-invasive third-party cookie tracking, faces a significant shift as browsers like Safari, Brave, and Firefox have already deprecated them. Google Chrome announced its parallel move with the “Privacy Sandbox Initiative” in 2019, proposing privacy-preserving advertising mechanisms. The extent to which Privacy Sandbox can deliver comparable ad effectiveness to the established third-party cookies system will likely determine its adoption as a widespread alternative. This paper presents the first user study evaluating the impact of Privacy Sandbox APIs on ad perception. Our findings show that users perceive Privacy Sandbox ads as less relevant and exhibit lower purchase intent compared to third-party cookie–based ads, without a corresponding increase in perceived privacy protection. These results contribute to the ongoing assessment of Privacy Sandbox as an alternative to third-party cookies.