Traffic & Channels
Ad Slot
An advertising placement/slot on a page or app where a creative is served.
An ad slot is a specific advertising placement on a page or app screen where a creative is served — defined by its position, size and format, and filled either by direct deals or programmatically through an ad server or SSP. The slot is the atomic unit of inventory: everything a network sells decomposes into slots.
For buyers, slot position drives economics more than most targeting settings: above-the-fold slots and first-screen app placements carry higher viewability and CPMs, while below-fold slots deliver cheap but often unseen impressions. When a network exposes placement or zone IDs, those are effectively slot identifiers — the level where whitelisting and blacklisting actually move campaign ROI.
In buyer speech
“Zone 4417 is a footer ad slot nobody scrolls to — blacklist it, it ate $30 with zero conversions.”