Glossary
What is signal loss?
Signal loss is the gap between the conversions that actually happen and the conversions your ad platforms can see and attribute. It is caused by ad blockers, browser privacy features such as Safari’s Intelligent Tracking Prevention, iOS App Tracking Transparency, short-lived cookies and missing consent. All of these stop browser-based tracking from reporting events.
Client-side tracking depends on a fragile chain: a script must load, cookies must survive, and a click ID must still be attached when the conversion finally happens. Every link can break: an ad blocker stops the pixel, Safari deletes the cookie after seven days, a redirect strips the click ID. Each break turns a real conversion into an invisible one.
The damage goes beyond reporting. Meta, Google and TikTok optimize delivery toward the conversions they can observe, so when a share of yours goes unreported, the algorithm learns from a partial picture. Reported CPA and ROAS drift away from reality, and budget flows toward what happens to be measurable rather than what performs.
Signal loss cannot be eliminated entirely, but a large share of it is recoverable: collect click IDs and visitor data first-party on your own domain, match orders back to the original click, and deliver events server-side through interfaces like the Meta Conversions API, deduplicated against your pixel so nothing is counted twice.