Published 2026-08-29 by destaque.ai, a Portuguese technology company that measures brand visibility in AI answers. Ler em português.
Method
16 questions in Portuguese, sent from Portugal with the market set to Portugal, on 25 August 2026. Thirteen ask for the best in a sector; three restate the banking question in different words, as a formulation control. Ten assistants: ChatGPT, Gemini, Grok, Claude, DeepSeek, Perplexity, Mistral, Google AI Overviews, Google AI Mode and Microsoft Copilot. Each question asked three times per assistant; identical repetitions counted once, leaving 616 observations. Mentions are literal name matches by declared patterns; choices are a human reading of every answer against a criterion written before the re-read and recorded answer by answer.
Findings
- The conversion rate from mention to choice ranges from 96% (supermarkets) to 20% (best Portuguese brands).
- 16 of 39 answers about private hospitals choose no hospital at all, the highest refusal rate in the study.
- Restating the banking question reverses the ranking: Santander is chosen in 36 of 39 answers to a top-5 request and in 7 when the question is a customer thinking of switching banks; ActivoBank goes the other way, 7 to 36.
- The most cited source in the whole study is a consumer association, followed by Reddit; no Portuguese general newspaper comes close.
- Three engines produce almost all of the criticism: Mistral, Gemini and Grok declare weaknesses; ChatGPT does so in 1% of its answers and Perplexity in none.
Two counts, not one score
Counting mentions does not distinguish a name buried in a list from a name the answer actually chooses, and that difference is what this study measures. So there is no composite score: there are two counts. Named is in how many answers the brand appears anywhere in the text. Chosen is in how many of those the answer distinguishes it above the others it itself names, through a place in an ordering, a verdict against a stated need, or the closing sentence where the model commits. Conversion is one divided by the other.
A superlative inside a description is not a choice, however strong. "World leader in cork" describes the brand on a shelf; it does not say it is the best Portuguese brand, which was the question asked. The full criterion is published on the Portuguese page and was written before the re-read, so that it could not be shaped by what appeared.
The same question, four ways, two rankings
Changing the wording of the banking question does not add noise to one ranking; it produces two. Asking for a top 5 returns the institutional hierarchy: Novo Banco appears in 87% of answers and Revolut in 8%. Asking what to recommend to someone living in Portugal inverts almost everything: Revolut rises to 90% and Novo Banco falls to 36%.
The reading extends to choices, and there it is harsher. From the most formal wording to the most personal, mentions rise from 245 to 341 while choices fall from 201 to 140. The question that most resembles a real customer produces the longest list and the smallest commitment. The practical consequence for anyone measuring AI visibility with a single prompt formulation: they are measuring one of the two rankings, and generally do not know which.
Who writes the answers
328 of the 616 observations show their sources, across 2,993 citations, and they are not the sites a brand usually monitors. The most cited domain in the whole study is the Portuguese consumer association DECO Proteste, with 105 citations concentrated in 6 of 14 question blocks. Reddit follows with 88 and appears in 13 of 14, making it the most transversal source in the study. Two foreign fintechs writing guides about Portuguese banks, Wise and Qonto, together account for 135 citations. Wikipedia appears 34 times in 2,993.
Per category, the dominant source changes completely. In telecommunications a single site accounts for 56 of the category's 220 citations. In the open question about the best company in the country, the dominant source is a workplace ranking. In private healthcare, the most cited source is the hospital group's own website, so the brands are themselves the source of the answer that ranks them.
Dataset
One row per brand per question: how many answers name it, how many choose it, and the conversion between the two. Plus category aggregates, the banking formulation control, the most cited domains, and declared weaknesses by engine.
Download the dataset (CSV). Licensed CC BY 4.0: reuse with attribution to destaque.ai.
Limitations
One collection day, 25 August 2026: there is no time series. The study measures prominence, not approval: a brand counts as chosen even when the next sentence says it is expensive. A brand named inside another ("Continente (Sonae Group)") credits a mention to each name, though not a choice. Sources are only those the engine displayed; answers given from memory carry none.
destaque.ai is a Portuguese technology company, based in Lisbon, that measures brand visibility in AI answers. This study is published in full in Portuguese at https://www.destaque.ai/estudo/mapa-empresas-portugal-2026. Methodology available on request: info@destaque.ai.