What Are Ad Impressions?
An ad impression is counted every single time your ad is displayed to someone, regardless of whether they interact with it. If the same person sees your ad three times, that’s three impressions — not three unique viewers.
Impressions vs Clicks vs Reach
These three metrics get mixed up constantly, but they measure different things:
- Impressions — total times an ad was shown (repeat views count each time)
- Clicks — how many of those impressions resulted in someone clicking through
- Reach — the number of unique people who saw the ad at least once
A campaign can have 50,000 impressions from just 5,000 unique people if each person saw it an average of ten times.
How Impressions Are Measured
Ad platforms count an impression the moment the ad is technically served and rendered on a page or screen, whether or not it was actually seen (this is why “viewability” exists as a separate, stricter metric). Impressions are typically reported alongside CTR (click-through rate) — impressions divided by clicks — to gauge how compelling the ad actually is once it’s in front of someone.
