Search Impression Share (SIS) is the percentage of impressions your Search campaign actually received divided by the total number it was eligible to receive. If your campaigns were eligible for 1,000 impressions and served 600, your SIS is 60%. The remaining 40% is lost — and the two columns that explain where it went tell completely different stories.
Impression Share Lost to Budget means your ads ran out of daily budget before serving all eligible impressions. The auction was available, your ad was eligible, but the spend cap stopped delivery. The fix is always budgetary: increase the daily budget, reallocate from underperforming campaigns, or concentrate the schedule to peak conversion hours so more budget lands when it matters.
Impression Share Lost to Rank means your Ad Rank was too low to compete in auctions your ads were eligible for. Ad Rank equals bid × Quality Score × expected extension impact. You lost these impressions not because you ran out of money but because your bid-adjusted quality wasn't high enough. Raising bids is one fix. Improving Quality Score is the more efficient fix because it compounds — a sustained Quality Score improvement reduces required CPC permanently.
How to find these metrics. Navigate to Campaigns → Columns → Competitive metrics. Add Search Impr. Share, Search Lost IS (rank), and Search Lost IS (budget). Sort by Lost IS (rank) descending to find which campaigns are losing the most impressions to Ad Rank problems.
What's a healthy Impression Share? Brand campaigns should target 90%+ impression share — losing brand queries to competitors is rarely worth the CPC savings. Non-brand campaigns operating at 60–80% impression share with strong ROAS are usually in a healthy position. Impression share below 40% on core high-intent campaigns signals significant visibility problems worth diagnosing before assuming bid increases are the fix.
Keyword-level impression share is more actionable than campaign-level for pinpointing problems. An exact match keyword with 20% IS in a campaign averaging 70% IS is a keyword that deserves either a bid adjustment or a Quality Score investigation — not a broad budget increase that raises all keywords indiscriminately.
Top of Page Rate and Absolute Top Rate add further context. 'Search top IS' measures the share of impressions appearing in the top positions above organic results. 'Search abs. top IS' measures the first position specifically. A high Impression Share with a low Absolute Top Rate means you appear frequently but rarely in the premium slot — for high-intent terms, that premium position often justifies the bid premium through higher conversion rates.
Impression Share traps. Don't chase 100% impression share at the expense of ROAS. Advertisers who set maximum IS as a goal often bid aggressively on unprofitable tail impressions. The goal is maximum eligible impressions at acceptable cost — not all possible impressions regardless of efficiency.
Seasonal interpretation. Impression Share drops during peak periods (Q4, seasonal events) often reflect increased auction competition, not campaign deterioration. Falling IS with stable CPCs and ROAS is usually normal during high-volume periods. Falling IS with rising CPCs signals bid pressure that may require a seasonal adjustment to maintain position on your most important terms.
Digital Face tracks Search Impression Share trends across all your campaigns, surfaces lost IS split by budget versus rank cause, and alerts you when high-value campaigns show significant visibility drops. Free plan at digital-face.nl, no credit card required.