{
  "slug": "search-impression-share",
  "name": "Search impression share",
  "aliases": [
    "Impression share",
    "IS"
  ],
  "definition": "The share of the paid impressions available to you in the auction that your ads actually received.",
  "category": "Paid search",
  "type": "share",
  "unit": "share of available auction impressions (stored 0 to 1, shown as a percent)",
  "direction": "higher-better",
  "verification": "verified",
  "calculation": "The average of Google Ads' own per-row search impression share across the rows in scope. The share itself is computed by Google Ads, not by Quattr; the semantic layer averages it.",
  "aggregation": "An unweighted average across keyword-day rows, not an impression-weighted one, a low-volume keyword counts the same as a high-volume one.",
  "grain": "One number per segment and date range, or one row per keyword or campaign.",
  "dimensions": [
    "keyword",
    "campaign_name"
  ],
  "requiredFilters": [
    "segment_id",
    "date_range"
  ],
  "sources": [
    "google-ads"
  ],
  "reports": [
    "paid-organic-overlap-report",
    "paid-search-performance-report"
  ],
  "skills": [
    "paid-efficiency-review",
    "paid-organic-balance"
  ],
  "verbs": [
    "paid_impression_share",
    "total_search_share"
  ],
  "rungs": [
    "R2"
  ],
  "levers": [
    "L8"
  ],
  "questions": [
    "How much of the available auction are we winning?",
    "Is our impression share improving?"
  ],
  "interpretation": "The coverage half of paid: not how well the ads performed, but how often they were eligible and shown at all. Read it beside the rank-lost measures, the gap between what you won and what you lost to rank is the auction ground a bid or quality change can recover.",
  "caveats": [
    "Called without a segment, the verb returns the list of tracked segments rather than a number, this metric is always per segment.",
    "The averaging is unweighted across rows, so a keyword with a handful of impressions moves the number as much as a keyword with thousands.",
    "Stored as a fraction between 0 and 1 while search market share is stored 0 to 100; combining the two without normalising erases the paid side.",
    "Click share is not surfaced anywhere in the product, the underlying column exists only on a campaign-grain dataset that no tool reads. Do not present impression share as a click-share proxy.",
    "The dataset has no country or device columns, so this metric cannot be sliced by geography or device."
  ],
  "freshness": "~1 day behind, Ads reporting settles overnight; same-day spend is provisional.",
  "failureModes": [
    "Assuming impression share can be broken down by country or device.",
    "Comparing impression share to search market share as if they were on the same scale."
  ],
  "notSameAs": [
    {
      "slug": "impression-share-lost-to-rank",
      "why": "One is what you won, the other is a specific named reason for what you did not win. They are separate columns and do not sum to a whole."
    },
    {
      "slug": "total-search-share",
      "why": "Impression share is paid coverage inside the ad auction; total search share is a combined estimate of paid and organic presence on the results page."
    },
    {
      "slug": "paid-impressions",
      "why": "Impressions count what you got; impression share expresses that as a fraction of what was available in the auction. Neither is derivable from the other in this product.",
      "mirroredFrom": "paid-impressions"
    },
    {
      "slug": "paid-ctr",
      "why": "CTR measures what happened after the ad was shown; impression share measures how often it was shown at all.",
      "mirroredFrom": "paid-ctr"
    },
    {
      "slug": "ctr",
      "why": "CTR is the share of impressions you received that clicked; impression share is the share of an available paid auction you appeared in at all. They share no numerator and no denominator, and click share, the metric people reach for when they conflate the two, does not exist in the product.",
      "mirroredFrom": "ctr"
    }
  ],
  "related": [
    "top-impression-share",
    "absolute-top-impression-share",
    "impression-share-lost-to-rank",
    "total-search-share-paid-leg"
  ],
  "workflows": [],
  "lastVerified": "2026-08-04"
}