AI Overviews (AIO) and AI Mode have rewritten the rules of the Google SERP through 2025-2026 — and with them, the playbook for diagnosing paid search underperformance. When AIO occupies the top of the result, ads still serve, but Impression Share (IS), CTR, and ad position behave in ways that legacy "raise bids, fix Quality Score" instincts cannot resolve.
What it means + benchmark
AI Overviews are Google's generative-answer block at the top of the SERP; AI Mode is the standalone conversational surface launched in March 2025. Both can show ads — Google confirms that Search, Shopping, and Performance Max ads are auto-eligible to appear above, below, or integrated into the AIO when commercial intent is detected and the creative is relevant to the AIO content (Google Ads Help — About ads and AI Overviews, 2025).
Benchmark (Seer Interactive, June 2024 → Sept 2025):
- Paid CTR on AIO-present queries: 19.7% → 6.34% (−68%)
- Organic CTR on AIO-present queries: 1.76% → 0.61% (−61%)
- Cited brands: +91% paid clicks vs. non-cited brands inside the AIO
- Ahrefs Dec 2025 update (300K keywords): top-ranking pages with AIO present see 58% lower CTR vs. matched non-AIO baselines (Ahrefs, 2025-12)
Source-conflict framing. Google's stated position is that "ads adapt" to the AIO surface and that advertisers do not need to take specific action — eligibility is automatic across 200+ markets where AIO is available. Operator-measured data tells a different story: significant IS and CTR loss on informational-intent queries, mobile devices, and verticals where Google withholds ads from the AIO block entirely (adult, alcohol, gambling, finance, healthcare, politics).
Top causes ranked
- Ad pushed below the AIO block — across the SERP sample, ads appear below the AIO ~25% of the time; in Healthcare, 64.6% of the time (Search Engine Land, 2025-12-03). Below-AIO position behaves more like below-the-fold than position 2 on a classic SERP.
- Informational-intent queries cannibalized by AIO —
how,what,best, comparison queries lose the most CTR. Transactional intent (buy,near me, branded) retains far better CTR. - Creative not relevant to the AIO content — Google's eligibility rule requires the ad to address both the query AND the AIO synthesis. Generic RSAs with no concrete offer/spec lose eligibility entirely on AIO-present auctions.
- Vertical excluded by Google — restricted verticals never show ads inside the AIO. IS loss here is structural, not fixable in-account.
- Mobile compression — AIO block consumes 100% of mobile above-the-fold; ads below are functionally invisible.
- No first-party audience signal — without Customer Match / Website-visitor segments, the auction can't differentiate your intent-qualified user from the broad informational searcher AIO satisfies.
- Brand not cited inside the AIO — cited brands earn 91% more paid clicks; absence from citation set compounds CTR loss (Search Engine Land, 2025-11-04).
Diagnostic checklist
Work top-down. The first three rows distinguish AIO-driven IS loss from classic bid/Quality Score IS loss — critical because the fixes differ.
| # | Check | Where | Threshold / signal |
|---|---|---|---|
| 1 | Search IS trend on informational keyword themes (last 90d) | Campaigns → Competitive metrics → segment by week | Step-change drop >15% on informational ad groups while transactional flat = AIO surface signal |
| 2 | Search lost IS (rank) vs lost IS (budget) split | same columns | If rank-loss grew but bids/QS unchanged → AIO is reordering position, not bid pressure |
| 3 | Vertical / category restriction check | cross-ref Google's restricted-vertical list | Healthcare/finance/gambling/alcohol/politics → AIO IS loss is structural |
| 4 | Manual SERP spot-check, mobile + desktop | Incognito on top 20 queries by cost | Count: AIO present? Ad above or below AIO? Brand cited in AIO? |
| 5 | CTR delta: informational vs transactional ad groups, 90d | Ad groups → segment by intent label | Informational CTR >40% below transactional = AIO erosion |
| 6 | Conversion rate on remaining AIO-query traffic | Search terms → filter to informational | CVR holding or rising on lower volume = quality-of-clicker improving; falling = wasted spend |
| 7 | Audience signal presence on Search + PMax | Audiences tab | No Customer Match + no Website visitors = no first-party lever to differentiate intent |
Fix paths
Order matters — bid changes are the last lever, not the first.
- Re-segment by query intent. Split ad groups (or campaigns) by informational vs transactional intent so AIO-driven CTR drag does not poison Smart Bidding signals on transactional themes. Cross-link search-query-mining for the workflow.
- Tighten creative to AIO-eligible content. Rewrite RSAs to mirror the answer shape AIO produces: concrete specs, prices, comparisons, named differentiators. Generic benefit copy loses AIO auction eligibility per Google's relevance requirement.
- Add first-party audience signals everywhere. Customer Match list (refreshed monthly) + Website visitor segment + Custom Segment by search history. Cross-link customer-match. On PMax, this directly feeds AIO matching; on Search, it powers audience-aware bid adjustments.
- Prune negatives on informational long-tail. When CVR on informational queries collapses post-AIO, the right move is to exclude the queries, not lower the bid. Use search-term reports to identify zero-conversion / low-CVR informational terms in the last 90d. Cross-link negative-keywords.
- Treat Quality Score as creative-relevance signal, not bid hack. AIO eligibility runs partly on the same expected-CTR / ad-relevance signals that drive QS. Fix landing-page-experience and ad-relevance first — both improve AIO auction wins. Cross-link quality-score, fix-keywords-quality-score-low.
- Test AI Max for Search on Search campaigns where keyword themes are heavily informational. AI Max expands matching using LLM understanding of query+landing-page semantics, which can recapture some AIO-cannibalized volume. Cross-link ai-max-for-search.
- Bid actions last. Only after 1-6, if IS loss persists on a positive-margin theme and the ad is consistently winning above-AIO position, consider tCPA/tROAS loosening or manual bid lifts. Lifting bids on a generic-RSA / no-audience-signal campaign just funds higher CPCs at the same low CTR.
Methodology note. Whitead does not yet have a dedicated aio_impact rule in production. The diagnostic surfaces through the interaction of existing rules: a step-change in Search lost IS (rank) on informational ad groups, combined with low_quality_score on the same ad groups and missing_audience_signals on the campaign, is the strongest signal that AIO surface change — not classic bid pressure — is driving the IS gap. The fix-priority logic intentionally defers any bid-change recommendation when the AIO surface signal is present: query-mix, creative relevance, and first-party signals must be addressed first, because additional spend on a campaign losing IS to AIO surface change typically increases CPC without recovering position.
When to escalate
Escalate to strategy review (not tactical in-Ads-UI fixes) when:
- IS loss is >15% on a converting campaign, restricted vertical = no, ad-above-AIO rate is already >60%, and creative + audience signals are already tightened. Remaining IS gap is structural to AIO surface — conversation moves to channel mix (Demand Gen, YouTube, organic-AIO citation strategy) rather than Search bid changes.
- Brand absent from AIO citation set on branded queries despite ranking organically — this is a GEO / AI-citation problem, not a Google Ads problem. Refer to content + structured-data team.
- Restricted-vertical (healthcare, finance, alcohol, gambling, politics) account with sustained IS loss — Google will not show ads in the AIO block. The structural fix is intent-level pivot away from AIO-dominated informational queries toward transactional / branded / non-AIO surfaces.
Related concepts
- Search lost IS — budget-limited playbook — the classic IS-loss diagnostic; use to distinguish AIO surface from budget cap.
- Low Search CTR diagnostic — AIO-driven CTR drop is a leading cause in 2026.
- Quality Score — feeds AIO eligibility; the same expected-CTR / ad-relevance signals matter.
- Negative keywords — first lever when informational CVR collapses.
- AI Max for Search — recapture some informational volume lost to AIO.
- Search query mining — workflow for fix path #1 and #4.
- Fix low Quality Score keywords — the finding-tied article behind fix path #5.
Sources
- About ads and AI Overviews — Google Ads Help, 2025
- Google Ads Highlights of 2025 — Google Ads Help, 2025
- A new generation of ads for the AI era of Search — Google blog, 2026-05-20
- Google AI Overviews drive 61% drop in organic CTR, 68% in paid — Search Engine Land (Seer Interactive data), 2025-11-04
- How AI Overviews are impacting ad position and the fight for top spot — Search Engine Land, 2025-12-03
- AI Overviews Reduce Clicks by 58% (update) — Ahrefs, 2025-12
- 4 strategic paid search pivots to survive Google's AI Overviews — Search Engine Land, 2026-01
- Google AI Overviews reduce organic CTR 61%, paid traffic 68% — PPC Land, 2025-11