In an analysis of 13 business-to-business (B2B) advertiser accounts, 61% of Google Ads Search spending was directed to search terms that Google did not disclose in its search terms report. Across the period studied (fourth quarter of 2025 through second quarter of 2026), this amounted to $960,175 of $1,564,322 in total advertising spend.
The proportion was consistent across the last 3 quarters, ranging from 60.8% to 62.3% of spending, and it appeared in every account examined. The account with the highest disclosure had 23% of its spending hidden; the account with the lowest had 90% hidden. No account had complete or even 75% reported search terms out of total search spend.
Background: keywords and search terms
In Google Ads, advertisers bid on keywords — words or phrases selected to trigger their ads, for example "running shoes." The actual query a user types is called a search term. A single keyword can match many different search terms due to Google's close variant matching algorithm, such as "best running shoes for beginners" or "running shoes for flat feet."
Google provides advertisers with a search terms report, which lists the queries that triggered their ads together with the clicks and cost attributed to each. Advertisers use the report to identify irrelevant queries, add negative keywords, and assess which actual queries drove conversions.
However, Google does not include every query in the report. Citing user privacy, it omits queries not searched by a sufficient number of distinct users, either grouping them into an unlabeled "other search terms" total or excluding them. In these cases a click occurred and spending was recorded, but the underlying query is not shown. Spending attributed to such undisclosed queries is referred to in this study as hidden.
Methodology
For each account and quarter, two figures were compared, both limited to Search campaigns. Display, Video, Demand Gen, Shopping, and Performance Max campaigns were excluded, as they do not produce a comparable search terms report.
- Total Search-campaign cost — the total spending reported for Search campaigns (the denominator).
- Visible search-term cost — the spending attributed to the individual search terms disclosed in the search terms report (the numerator).
The hidden clicks percentage was calculated in the same way using clicks. The study reports hidden spending and clicks rather than a count of hidden terms, because undisclosed terms cannot be enumerated. Where accounts also ran Performance Max or Shopping campaigns that contribute search terms to the report, those non-Search terms were excluded so that the ratio reflects Search campaigns only. All monetary values are in United States dollars.
The hidden figure includes all Search spending not attributed to a disclosed query, including spending on search-partner and expansion inventory that generates no query record. Such spending is likewise absent from the search terms report.
Results
Share of spending hidden
Weighted by spending, the hidden share was between 60.8% and 62.3% in each quarter. Across the accounts examined, the majority of Search spending was directed to undisclosed queries. Weighting each account equally, rather than by spending, produced a similar range of 62–64%, indicating that the result was not attributable to a single large account.
Hidden spending in dollars
Search spending divided into disclosed and undisclosed portions, by quarter.
Quarterly hidden spending increased from $289,000 to $374,000 as total budgets grew. The disclosed portion did not exceed 40% of spending in any quarter.
Variation across accounts
Hidden Search spending as a percentage of total Search spending, by account (Q2 2026), anonymized. The dashed line indicates the portfolio spend-weighted average.
The hidden share ranged from the low 30s to the mid-80s (percent) within a single quarter. No account disclosed more than approximately two-thirds of its Search spending. The account with the highest disclosure was a brand-focused retailer, for which branded queries account for much of the report; the accounts with the lowest disclosure relied heavily on broad match, under which a larger share of queries falls below Google's disclosure threshold.
Hidden clicks and cost per click
Hidden clicks (click-weighted, 52.8% to 54.4%) were lower than hidden spending (approximately 61%) in each quarter. Because a larger share of spending than of clicks was hidden, undisclosed queries had a higher average cost per click than disclosed queries.
Implications
Platform transparency
Because the majority of Search spending is directed to undisclosed queries, the search terms report reflects a portion of activity rather than a complete record. Advertisers can review and act on only the disclosed portion. Greater disclosure — for example, aggregated reporting or a lower withholding threshold — would increase the share of spending available for review, subject to the privacy considerations Google cites for the current thresholds.
Independent measurement
Where a majority of spending is attributed to undisclosed queries, in-platform search-term reporting provides limited visibility into how that spending is allocated. First-party measurement methods — such as server-side conversion tracking, integration of outcomes with customer relationship management (CRM) systems, and holdout or incrementality testing — assess advertising outcomes independently of the platform's own search-term reporting.
Limitations & caveats
- The search terms report has always withheld some queries for privacy; this study measures the scale and persistence of that gap, not its existence.
- Hidden share tends to be higher for very small, new, or long-tail accounts; the study reports spend-weighted and equal-weighted figures together and segments by size to account for this.
- Search-term totals can differ slightly from the Google Ads interface due to attribution windows and rounding; quarter-level aggregates are used throughout.
- Scope is limited to advertising_channel_type = SEARCH for both numerator and denominator; Performance Max and Shopping search terms were removed where present. Performance Max is outside the scope of this study.
- The sample comprises 13 B2B accounts managed by a single agency and is not a representative sample of all advertisers.
Appendix — account-level data (anonymized)
Hidden Search spend % by account and quarter. Account identities and exact spend are withheld; size tier is shown instead (Large ≥ $30K/quarter average, Mid $13–30K, Small < $13K).
| Account | Size tier | Q4 2025 | Q1 2026 | Q2 2026 |
|---|---|---|---|---|
| Account A | Large | 89.6% | 85.4% | 85.4% |
| Account B | Small | 72.5% | 74.1% | 75.0% |
| Account C | Mid | 78.8% | 75.5% | 70.0% |
| Account D | Large | 62.1% | 65.2% | 68.7% |
| Account E | Small | 70.9% | 76.0% | 67.5% |
| Account F | Small | 63.0% | 62.8% | 67.2% |
| Account G | Mid | 57.2% | 63.4% | 66.8% |
| Account H | Mid | 58.1% | 64.0% | 65.2% |
| Account I | Mid | 88.2% | 67.5% | 56.9% |
| Account J | Large | 51.3% | 53.4% | 55.0% |
| Account K | Small | 54.3% | 51.3% | 51.7% |
| Account L | Mid | 44.2% | 45.3% | 48.5% |
| Account M | Mid | 37.4% | 22.9% | 32.3% |
Size tiers: Large ≥ $30K/quarter average, Mid $13–30K, Small < $13K.
Portfolio summary
| Metric | Q4 2025 | Q1 2026 | Q2 2026 |
|---|---|---|---|
| Hidden spend % (spend-weighted) | 60.8% | 60.8% | 62.3% |
| Hidden spend % (simple average) | 63.7% | 62.1% | 62.3% |
| Hidden spend % (median account) | 62.1% | 64.0% | 66.8% |
| Range — lowest account | 37.4% | 22.9% | 32.3% |
| Range — highest account | 89.6% | 85.4% | 85.4% |
| Hidden clicks % (click-weighted) | 52.8% | 51.9% | 54.4% |
| Total Search spend | $476,409 | $487,917 | $599,997 |
| Hidden Search spend | $289,470 | $296,697 | $374,008 |