Media Rating Council (MRC) viewability standards dictate programmatic buyer willingness. Sites falling below 65% viewability face severe algorithmic bid penalties and DSP blacklisting.
Defining the MRC Standard
For display ads, the MRC standard requires at least 50% of the advertisement’s pixels to remain in view for a minimum of one continuous second. For large-format display units (242,500 pixels or larger), the threshold adjusts to 30% of pixels in view for one second. For digital video, 50% of pixels must remain in view for two continuous seconds.
Technical Tactics to Elevate Domain Viewability
- Intersection Observer API: Never trigger impression beacons until the target container enters the active viewport threshold.
- Adaptive Slot Height: Reserve exact layout dimensions via CSS
min-heightto prevent content reflows that push banners out of sight. - Sticky Footer Banners: A mobile-optimized 320×50 anchor banner that remains docked to the bottom of the viewport maintains 85%+ viewability across entire reading sessions.