Impression
When your ad is displayed to a user, regardless of whether they interact with it.
The basic unit of ad exposure.
What Counts
Ad appears in user's viewport (viewable impression standard), ad loads on page even if user doesn't scroll to it (served impression), ad renders for minimum duration (typically 1 second for display ads).
Different platforms use different standards—some count any served ad, others require viewability.
Why It Matters
Impressions are the denominator in most advertising metrics: conversion rate (conversions ÷ impressions), CTR (clicks ÷ impressions), CPM (cost per 1,000 impressions).
Understanding impression counting methodology is essential for comparing performance across platforms.
Web3 Consideration
In wallet-based attribution, an impression typically means an ad was served to a specific wallet address, enabling precise tracking of which wallets saw ads and later converted.