Third-party Cookies

Third-party cookies are tracking codes placed on a user's device by a website other than the one they are visiting.

Why it matters

Enable cross-site tracking for personalized ads.
Impact user privacy and data protection.

How to measure

Track cookie presence via browser developer tools.
Analyze over user sessions and interactions.

Details

Third-party cookies are primarily used for tracking user behavior across different websites to build detailed user profiles. This data is often used for targeted advertising and analytics. In a mobile context, third-party cookies can affect app performance and user experience, as they may slow down loading times and raise privacy concerns. Developers and growth teams need to be aware of regulations like GDPR and CCPA that restrict the use of third-party cookies, requiring explicit user consent.

As browsers increasingly block third-party cookies, alternative tracking methods such as first-party cookies and server-side tracking are gaining traction. Mobile engineers should consider these alternatives to ensure compliance and maintain effective user tracking.

Examples & formulas

An example scenario involves a user visiting an e-commerce site, where third-party cookies track their browsing to display relevant ads on other sites. With restrictions, this tracking is limited, affecting ad personalization.

Common mistakes

Ignoring privacy regulations can lead to legal issues; always ensure compliance.
Over-relying on third-party cookies can reduce effectiveness as browsers block them; diversify tracking methods.