Impression Share
Impression Share is the percentage of impressions your ads receive out of the total impressions they were eligible to get, showing how much of the available audience you are actually reaching.
In depth
Impression share is calculated as impressions received divided by total eligible impressions, and platforms break the shortfall into two causes: lost share due to budget and lost share due to ad rank. Budget-lost share means you ran out of money and stopped showing, while rank-lost share means your bid or Quality Score was too low to win the auction. This split is diagnostic gold, because it tells you precisely whether to spend more or improve quality rather than guessing at why a campaign is underperforming.
The common pitfall is chasing 100% impression share on every keyword, which is usually wasteful, because the last slice of available impressions tends to come from low-intent searches that convert poorly. The smarter play is to grow share on your highest-converting, highest-intent terms and let low-value queries go. In a quiz-funnel strategy, this pairs naturally with downstream measurement: increase impression share where the traffic produces strong quiz-completion and qualified-lead rates, and pull back where extra reach only adds cost without adding pipeline.
Example in practice
Frequently asked questions
What does lost impression share tell me?
It splits into share lost to budget and share lost to ad rank, pinpointing why you missed impressions. Budget loss means you should consider spending more, while rank loss means you need a higher bid or better Quality Score.
Should I aim for 100% impression share?
Usually not, because the final impressions often come from low-intent searches that convert poorly and inflate costs. It is smarter to maximize share on your highest-converting, highest-intent keywords.
How do I increase impression share?
Raise bids or budgets to fix budget-lost share, and improve ad relevance and landing pages to fix rank-lost share. Tying changes to quiz-completion and qualified-lead rate ensures the extra reach is actually worthwhile.