Metrics
Viewability
Percentage of impressions that met MRC's 'in-view' standard.
Viewability is the percentage of served impressions that met the MRC viewability standard: 50% of pixels in-view for at least 1 second (display) or 2 seconds (video). Below 70% viewability is poor; tier-1 publisher inventory clears 75–90%. Programmatic buyers contract minimum viewability thresholds (e.g., '85%+ measured-viewable') to filter out low-quality placements at the bid layer.
Example
Programmatic display campaign reports 92% measured viewability across tier-1 publishers but 41% on a long-tail site that auto-refreshes ad slots every 15 seconds — operator adds the long-tail site to a blocklist.