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)-35%
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.
Learn more: How SealMetrics Works · Calculate Your Data Loss