Impression
One instance of an ad being served — not necessarily seen, and not necessarily by a person.
The gap between served, viewable and seen is where most advertising disagreements live. An ad served below the fold and never scrolled to is an impression. So is an ad served to a data-centre bot.
When a publisher quotes an impression number from their own ad server and a buyer measures a smaller one, both can be honest: they are counting at different points in the chain, with different filters. Agree whose count settles the invoice before the campaign runs.
How LinkBourse handles it
Our impression count is recorded server-side at the point the pixel is requested, filtered for invalid traffic, and attributed to the property the placement was booked on — a request whose referer is not the booked property is excluded rather than counted.
Terms it depends on
- CPM
- The price of one thousand ad impressions — the standard unit for buying reach rather than outcomes.
- Viewability
- Whether an ad was actually rendered in a position where a person could have seen it, usually defined as 50% of pixels for one second.
- Invalid traffic
- Clicks and impressions that did not come from a real person acting on the ad — bots, prefetchers, repeat automation, and traffic from somewhere other than the booked property.