Standard browser pixels lose 25% to 40% of conversion events due to Safari ITP 24-hour cookie limits, iOS privacy restrictions, and ad-blockers. Server-Side GTM and Google Tag Gateway route beacons through your custom subdomain (data.yourdomain.com) via Google Cloud Run, setting 1st-party HTTP cookies with 365-day persistence and feeding ad algorithms 100% accurate purchase signals.
- Safari ITP Mitigation: Upgrades 24-hour capped client cookies to 1-year server cookies.
- AdBlocker Resilience: Requests to custom subdomains are never blocked by ad filters.
- Cloud Run Edge Routing: Sub-50ms server response times guarantee no impact on Core Web Vitals.