Third-Party Cookies

Third-party cookies are HTTP cookies set by a domain different from the one the user is currently visiting. When you visit example.com and a cookie is set by ads.google.com or facebook.com, those are third-party cookies. They have historically been the backbone of digital advertising, enabling cross-site tracking, behavioral profiling, retargeting, frequency capping, and conversion attribution across multiple websites. The lifecycle of a third-party cookie in advertising works as follows: a user visits Website A, which loads an advertising tag from AdNetwork.com. AdNetwork.com sets a cookie on the user's browser under the AdNetwork.com domain. When the user later visits Website B, which also loads AdNetwork.com tags, the same cookie is sent to AdNetwork.com, allowing it to recognize the user across both sites and build a browsing profile for targeted advertising. This cross-site tracking capability made third-party cookies enormously valuable for advertising — but also raised significant privacy concerns. Major browsers have been systematically restricting and blocking third-party cookies: Safari's Intelligent Tracking Prevention (ITP) blocks them by default since 2020, Firefox Enhanced Tracking Protection (ETP) blocks them by default, and Google Chrome has announced plans to restrict them (though timelines have shifted). The deprecation of third-party cookies has fundamentally disrupted digital advertising, driving adoption of privacy-preserving alternatives: first-party data strategies, server-side tracking (Meta CAPI, TikTok Events API), Google's Privacy Sandbox (Topics API, Protected Audience), contextual advertising, and consent-based data collection. For businesses, this shift means that collecting proper consent and building first-party data relationships is no longer optional — it is the foundation of sustainable digital marketing. Arqam360 helps businesses navigate this transition by collecting proper consent, forwarding consented events server-side to ad platforms, and enabling audience activation on first-party data.