AI Recommendation Stability
What marketers need to know about how AI decides which brands to recommend
Noriko Yokoi, Ph.D., Thorsten Linz, and the 3cubed.ai Research Team
Across 26 unaided buyer questions, four AI engines, and three controlled conditions.
With live web retrieval on, repeat questions often produced a different top brand.
Only 7 of 26 questions produced the same top brand across all four engines.
The typical brand appeared in just 1 in 10 responses for its own category question.
The top 10 cited domains accounted for 28.6% of 3,059 source citations.
Why this study matters
Buyers increasingly ask AI assistants for recommendations instead of comparing a page of search results. This changes the visibility problem for brands. A single AI answer can name a short list of vendors, source domains, or service providers, and the buyer may never inspect the wider market.
The question behind this study was simple: once a brand earns an AI citation, does it stay cited? The answer was no. AI recommendation is not a fixed position. It behaves like a shifting probability that changes by prompt, engine, retrieval source, and time.
How the study was run
The study was pre-registered before data collection. Research questions, hypotheses, the query set, segment assignments, engine choices, experimental conditions, extraction rules, and primary metrics were locked in advance.
| Engine | Model version | Query coverage |
|---|---|---|
| ChatGPT | GPT-5.5 | 26 queries |
| Gemini | Gemini 3.5 Flash | 26 queries |
| Claude | Claude Sonnet 4.6 | 14 queries |
| Perplexity | Perplexity Sonar | 26 queries |
| Condition | What it means | What it isolates |
|---|---|---|
| Floor | Minimum randomness, no live web search | Model-level instability |
| Sampled | Normal randomness, no live web search | Generation variation |
| Web | Normal randomness, live web retrieval on | Real-world retrieval variation |
Finding 1: AI recommendations are not stable
Even with randomness minimized and live web search off, identical questions returned the same top brand only 78% to 87% of the time, depending on the engine. With live web retrieval on, consistency dropped to 48% to 68%.
| Engine | RCS floor | RCS sampled | RCS web |
|---|---|---|---|
| ChatGPT | 0.78 | 0.78 | 0.48 |
| Gemini | 0.78 | 0.67 | 0.54 |
| Claude | 0.87 | 0.69 | 0.50 |
| Perplexity | N/A | N/A | 0.68 |
Finding 2: Engines often disagree
Across 26 buyer questions tested on all four engines, only 7 questions, or 27%, produced unanimous agreement on the top brand. A brand can lead on one engine and be absent on another, which makes single-engine tracking incomplete.
Finding 3: Most brands appear rarely
Only 2.4% of brand-question combinations reached a 100% appearance rate. 85.7% fell below 50%, and the median appearance rate was 10%. In practice, a brand that "appears in AI" may show up in 1 of 10 responses, not 9 of 10.
Finding 4: Gatekeeper publications shape the answer
The study found 376 unique cited domains across all engines and questions. The top 10 domains accounted for 28.6% of all 3,059 source citations. Chambers, Forbes, and TechRadar alone accounted for 15.8%.
| Publication | Times cited | Citation share | Who it matters for |
|---|---|---|---|
| Chambers | 250 | 8.2% | Legal services |
| Forbes | 122 | 4.0% | Finance, business, consumer |
| TechRadar | 110 | 3.6% | B2B software, consumer tech |
| U.S. News Best Law Firms | 70 | 2.3% | Legal services |
| Tom's Guide | 67 | 2.2% | Consumer tech, software |
| RTINGS.com | 67 | 2.2% | Consumer electronics |
| NerdWallet | 51 | 1.7% | Personal finance |
| Legal 500 | 49 | 1.6% | Legal services |
| Vault | 47 | 1.5% | Legal, career |
| Sleep Foundation | 43 | 1.4% | Consumer health, mattresses |
What marketers should do next
- Measure appearance rate, not a yes-or-no snapshot.
- Track across ChatGPT, Gemini, Claude, and Perplexity.
- Run repeated checks because one-off scans miss instability.
- Identify the source domains AI engines cite most in your category.
- Build coverage in those gatekeeper publications, then monitor drift.
Run this measurement for your brand
Findabl tracks your buyer questions across all four engines, maps the source domains shaping the answer, and turns missed citations into actions.
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The PDF includes the full methodology, limitations, appendix query list, and references.
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