Server-side tracking sends conversion data from your server (not the browser) to Meta/Google, recovering 20-40% of the data lost to cookie blocking, ad blockers and iOS privacy changes.
Server-side tracking uses a first-party server (e.g. GTM server container, Stape) to forward conversion events to ad platforms via CAPI/Measurement Protocol instead of relying on the browser. For UK financial advisers this typically recovers 20-40% of events lost to Safari ITP, iOS ATT, ad blockers and consent banners. The result is cleaner ad platform learning and more accurate ROAS reporting.