Data Loss in Analytics
The gap between actual website traffic and what analytics tools report. Caused by consent rejection, ad blockers, browser restrictions, and data sampling. Typically 70-87% in the EU.
The cascade of losses
Data loss in web analytics is not caused by a single factor. It is a cascade where each loss compounds on the previous one:
Consent banner rejection (EU)-55%
Accept on page 2 (no source attribution)65% of accepted
Correct traffic source attribution~16%
Ad blocker blocking-40%
ITP / ETP cookie limits-40%
Data sampling-25%
Cumulative: GA4 reports~13% of real traffic
Use the data loss calculator to see the specific numbers for your traffic and region.
The business impact
Data loss is not just a measurement problem. It directly affects revenue attribution, campaign optimization, and board reporting. When your analytics show 10,000 visitors but 70,000 actually visited, every decision built on that data is compromised.