Impression share is the proportion of times your ad could have shown against the times it did. Eighty percent means you appeared in four out of every five opportunities.
Why you lose the rest
- Budget. You ran out of money before the day ended. Shown in reports as lost to budget.
- Rank. Your bid or ad quality was not high enough. Shown in reports as lost to rank.
How to use it
The split tells you which lever to pull. Losing to budget with a good cost per enquiry means the account is profitable and starved, so raise the budget. Losing to rank means fixing relevance and landing pages before bidding higher.
Using impression share to guide your budget
Typically, we review impression share every month as part of managing Google Ads accounts, because it tells us which lever to pull next.
For example, Google’s own impression share documentation breaks down each of the lost-impression-share metrics in more detail.
Specifically, check search and shopping figures separately, since the two behave very differently even within one account. Similarly, a sudden drop is often the first visible sign of a billing or policy issue elsewhere in the account. Notably, chasing a higher number for its own sake can waste budget on searches that never convert.
However, a healthy account still loses a portion of its impressions on purpose, simply because bidding on everything would waste money on searches that never convert. Instead, treat the metric as a diagnostic, not a target to maximise for its own sake.
Notably, the two lost-impression-share figures rarely move at the same time, so watching them separately tells you far more than a single combined number ever could. Reviewing both together each month keeps budget decisions grounded in what actually happened, not what you assume happened.
For example, a spike right after a competitor pauses their campaign is a useful signal worth noting in your own reporting.
