Ad Impression

Definition:
An ad impression is counted when an ad is served and appears on a user’s screen, whether or not the user interacts with it.

Why it matters:
Impressions are the baseline metric for reach in digital advertising. However, high impressions with low engagement may indicate poor targeting or quality issues.

How it works:
Platforms count an impression when the ad is fetched and rendered (fully or partially) on a webpage or app. Standards for "viewable impressions" vary by platform.

Best practices:

• Track impression vs. viewable impression rates

• Focus on placements with high engagement, not just reach

• Avoid low-quality inventory with artificially inflated impressions