Full Answer
Third-party tracking is the default for most websites: a JavaScript snippet from Facebook, Google, or TikTok runs in the visitor's browser and sends data from a third-party domain. Browsers classify this as cross-site tracking and restrict it. Safari's ITP limits these cookies to 7 days. Firefox's Enhanced Tracking Protection blocks requests outright. Ad blockers intercept them completely.
First-party tracking routes events through infrastructure you control—a dedicated server on your own subdomain or direct server-to-server API calls. Because requests originate from your domain, browser restrictions do not apply. Conversion data reaches its destination regardless of ad blockers, ITP, or privacy settings.
GDPR compliance also improves: data processing happens on infrastructure you control before being forwarded to ad platforms. For WordPress stores, first-party server-side tracking recovers the 30-40% of events that third-party scripts routinely miss.