Google Shopping Ads Have A Reverse Crocodile Effect With AI Overviews

Ever since Google accelerated the rollout of AI Overviews across commercial search results, organic publishers and SEO practitioners have confronted an alarming operational reality known colloquially as the "crocodile effect" or "the great decoupling." On organic dashboards, impressions climbed into the stratosphere as AI answers synthesized and referenced web content, while actual click-through rates (CTR) plunged precipitously, forming the widening, gaping jaws of a crocodile.

Yet within Google's paid monetization engine—specifically across Google Shopping ads—the exact opposite phenomenon is now unfolding.

In an exhaustive empirical investigation spanning 175 billion impressions conducted by Mike Ryan, Head of Ecommerce Insights at Smarter Ecommerce, paid search telemetry revealed a striking structural inversion: Shopping ad impressions are contracting while click-through rates are sharply climbing.

*Above: Data telemetry showing the divergent divergence between shopping ad impressions and click-through rates.*

The quantitative shift observed across commercial retail campaigns between mid-2025 and mid-2026 presents a clean mathematical antithesis to the organic ecosystem:

• Impression Contraction: Median Shopping ad impressions declined from approximately 1.85 million to 1.40 million, marking an inventory drop of nearly 24%.
• CTR Expansion: Over the identical 12-month evaluation window, median Shopping click-through rates climbed from 1.20% to nearly 1.55%, representing a relative efficiency gain exceeding 29%.

For years, digital marketing theory dictated that macro paid search trends move in lockstep with organic search behavior. When Google introduces rich UI modules that cannibalize the above-the-fold canvas, both organic listings and paid listings historically lost attention. But as Ryan demonstrated through multi-market auction logs, the interaction dynamic between AI Overviews and Google Shopping operates under fundamentally distinct algorithmic mechanics.

Mike Ryan encapsulated the paradox in his research breakdown:

"Ever since AIOs launched, publishers have been gaining impressions and losing clicks: the dreaded SEO 'crocodile effect.' For Shopping ads, it's the opposite. But why?... Google checks the predicted CTR of a given query and serves AIOs preferentially for lower-probability queries in order to preserve revenue. Thus CTR climbs partly due to a shrinking denominator (fewer impressions) and partly due to selection/pruning (higher click propensity)... If true, I'd view this as a bridging strategy."

Why would Google willingly contract ad impressions on its flagship retail ad format? The answer lies in Google's internal auction scoring mechanism and predicted click-through rate ($pCTR$) thresholds.

In Google Ads auctions, Ad Rank is determined by a combination of the advertiser's bid, ad quality, context, and $pCTR$. On ambiguous, exploratory, or top-of-funnel research queries (e.g., "what to look for when buying hiking boots"), showing multi-product Shopping carousels often yields mediocre user engagement. Users exploring concepts or evaluating categories rarely convert immediately on direct product listing ads (PLAs).

Under Google's generative search architecture, the search engine appears to be actively routing these lower-probability commercial queries toward AI Overviews. The AI Overview synthesizes category considerations, product attributes, and buyer guides directly inside the search interface.

Simultaneously, Google suppresses or eliminates Shopping ad carousels on these marginal SERPs. Instead, Google reserves product carousels for high-intent, bottom-of-funnel queries where the predicted click propensity is exceptionally high—such as specific SKU searches, brand-model combinations, and explicit transactional inquiries.

The mathematical outcome of this selective suppression is two-fold:

1. 1.The Denominator Effect: Because Google is no longer spamming Product Listing Ads across weak, top-of-funnel queries, total ad impressions drop significantly.
2. 2.The Selection Effect: The impressions that remain are concentrated in hyper-targeted transactional auctions where consumers have their credit cards in hand, naturally driving median CTR upward to 1.55%.

Ryan categorizes this architectural behavior as an intentional "bridging strategy." Google faces the delicate challenge of transforming its primary interface into an agentic, answer-driven engine powered by Gemini while safeguarding the quarterly revenue engine of Google Ads.

Flooding AI Overviews with low-quality, irrelevant Shopping units would degrade both the generative user experience and advertiser return on ad spend (ROAS). By acting as an aggressive gatekeeper—pruning ad inventory where commercial intent is diffuse and focusing paid units where purchase intent is verified—Google preserves cost-per-click (CPC) pricing power and advertiser confidence.

Advertisers are not seeing their budgets evaporate into low-intent click wastage; rather, they are paying for high-intent visits that demonstrate tangible purchase velocity.

For performance marketing directors, PPC leads, and e-commerce growth executives managing Performance Max and Standard Shopping campaigns, this telemetry mandates key strategic adjustments:

1. 1.Audit Query Coverage in Search Terms Telemetry: Expect gross impression volume to remain constrained on broad commercial keywords. Advertisers who evaluate campaign vitality purely on raw impression reach will misdiagnose healthy inventory pruning as campaign underdelivery. Focus on conversion rates, absolute click volume, and ROAS.
2. 2.Strengthen Product Feed Granularity: Because Google is reserving Shopping impressions for precise transactional matching, feed optimization is paramount. Ensure merchant feeds contain rigorous GTINs, detailed product titles, variant attributes, and clear category taxonomy so automated bidding algorithms can match listings during high-pCTR query evaluation.
3. 3.Harmonize Organic Generative SEO with Paid Shopping: While Shopping ads capture bottom-of-funnel clicks, AI Overviews are absorbing mid-funnel category exploration. Brands must simultaneously invest in Generative Engine Optimization (GEO) to earn citations within AI Overviews, ensuring organic presence during initial consideration followed by Shopping ad dominance at the point of sale.
4. 4.Prepare for Post-Bridge Monetization: As Google refines native shopping experiences directly inside AI Overviews and AI Mode, the "bridge" will eventually shift toward integrated conversational commerce. Maintaining pristine merchant data today ensures seamless eligibility when Google deepens transactional checkout features inside Gemini-powered overviews.