Impression Share

Impression Share is the percentage of total available impressions that a video, ad, or piece of content actually received, compared to the total number of times it was eligible to be shown. In advertising, impression share measures how often an ad appeared relative to how often it could have appeared based on targeting criteria and budget. For YouTube creators, a related concept is the ratio of impressions to views — a high impression count with a low click-through rate indicates the thumbnail or title is not compelling enough to drive clicks. Improving impression share in advertising requires increasing bids, budgets, or quality scores.