GEO Advertisement: your brand mentioned on ChatGPT, Gemini and Perplexity

What GEO Advertisement is and why there is no shortcut

When a potential customer types into ChatGPT "best accounting firm in Porto" or "physiotherapy clinic near me", they do not receive a list of links: they receive a text answer. That text mentions some brands and ignores others. There is no button to pay and appear in that answer.

What does exist is work on the sources AI uses to build the answer: the brand's website, Google Business Profile, social media, reviews and what the press or directories say about it. It is the same foundation as our GEO consulting, here directed at getting your brand into the answers about your sector. To understand the concept at its base, the article what is GEO explains how AI search works.

GEO Advertisement is the service focused on that specific goal: getting your brand onto ChatGPT, Gemini and Perplexity, with a measured starting point and a monthly report that shows the progress. It starts with a MessGEO analysis.

What MessGEO is and what it measures

MessGEO is our own GEO measurement tool. Before starting any work, we ask the questions your brand's customers would ask an AI tool, in European Portuguese and in English, to ChatGPT, Gemini and Perplexity.

We record three things:

• Appearance frequency: in how many answers, out of how many prompts tested, the brand name appears. We express this as a percentage of the measurement cycle.
• Description quality: when it does appear, what does the AI say? Is the name correct? Are the services and location right? Is there wrong or outdated information?
• Sources cited: which websites, articles or profiles does the AI cite when it talks about your brand, or which brands does it mention instead of yours?

This initial score is the starting point. At the end of each month we repeat the same prompts and report the change. AI tool responses vary, so we measure several times on different days and calculate an average; it is the trend over time that counts, not a single result.

Why AI cannot guarantee positions

This needs to be clear: there is no way to buy or guarantee that a brand appears in a ChatGPT, Gemini or Perplexity answer. These tools do not disclose how they choose what to cite, and responses change depending on the question, the language, the context and the date.

What does exist is a set of practices that increase the likelihood of a brand being mentioned and well described:

1. The sources AI consults are complete and consistent with each other.
2. The language used matches the European Portuguese the customer uses in questions.
3. The website has structured data that lets AI identify the business without guessing.
4. There are mentions in independent editorial sources, such as press and directories, that AI values.
5. Reviews exist, are recent and the brand's responses are visible.

None of these actions guarantees an answer. All of them increase the brand's readiness for AI search, and that is what we measure.

What is happening in Portugal: the Portuguese are already asking AI

Portugal adopts generative AI tools faster than the European average. According to Eurostat, in 2025, 38.7% of Portuguese aged 16 to 74 had used at least one generative AI tool in the previous three months; the EU average is 32.7%. Among those aged 16 to 24 the rate rises to 76.5% in Portugal, against 63.8% in the EU. And 19.9% of the Portuguese already use these tools for work, against 15.4% in the EU.

In addition, since March 2025 Google has been showing AI Overviews (Visao geral de IA) at the top of many search results in Portugal, in Portuguese and in English. For some searches, the customer reads the AI-generated answer and no longer clicks on links.

What this means for a business in Portugal:

• A portion of your potential customers no longer reaches your site through traditional Google; they arrive through the answer that AI writes.
• This group is younger and uses digital tools more frequently.
• If your brand is not in the sources AI consults, it simply does not exist for that group of customers.

European Portuguese: the detail that makes the difference in AI answers

AI tools learn from text published on the internet. The majority of Portuguese text on the internet comes from Brazil, a much more populous country. As a result, when a customer asks a question in European Portuguese, the tool may respond in Brazilian Portuguese and may favour Brazilian brands or sources.

The difference is not only one of vocabulary, though vocabulary matters: the Portuguese customer says "telemovel", "marcacao", "pequeno-almoco"; the Brazilian customer says "celular", "agendamento", "cafe da manha". But the difference is also in search intent: when a customer in Lisbon searches for "aesthetic clinic with natural results", they are using a set of words, a cultural context and a price expectation that do not correspond to a similar search in Sao Paulo.

What we do:

1. All content we create is in European Portuguese, with the vocabulary and AO1990 spelling that customers in Portugal use.
2. The prompts we send to ChatGPT, Gemini and Perplexity in MessGEO are written in European Portuguese, as a customer in Portugal would phrase them.
3. We identify whether the sources that talk about your brand use Brazilian Portuguese, and we correct what is within your control.

The sources AI reads: where we work

When an AI tool decides what to say about a brand, it does not consult a single page. It builds the answer from a set of sources it recognises as relevant and reliable. Those are the sources we work on.

The brand's website

This is the source with the most weight and the only one entirely within your control. For AI to be able to read the website and use its content in answers:

• The first sentence of the home page says what you do, for whom and where, unambiguously.
• Company data including full business name, address, phone and email are visible in text, not only in an image.
• There is structured data in the code, with the machine-readable identity card of the business.
• The robots.txt does not accidentally block the crawlers used by AI tools.
• Service pages are written in plain text, not only in images or slideshows.

Google Business Profile

Gemini and Google's AI Overviews consult the Google Business Profile as a priority. An incomplete or outdated profile is one of the most common reasons AI gives wrong information about a business.

• The company name must be written exactly the same in the profile and on the website.
• The main category should describe the business as precisely as possible.
• Opening hours must include national and municipal public holidays. In Lisbon, on 13 June, many businesses close; in Porto, on 24 June. A wrong opening time leads AI to misinform the customer.
• Photos should be recent and show the space, product or service clearly.

Reviews and replies

The text of reviews is one of the largest bodies of text AI tools read about any business. In Portugal, the ones that matter most are Google Reviews for all sectors, TripAdvisor and TheFork for restaurants and tourism, and Booking.com for accommodation.

Every reply the brand gives to a review is another opportunity to say, in its own words, what it does and where it is located. A short, personal reply that naturally includes the name of the service and the location is one of the simplest and most useful practices in GEO.

Press and editorial sources

Whatever the brand writes on its own website, if it does not appear on other authoritative sites, AI finds it harder to recommend it. Perplexity in particular cites the sources it uses. In Portugal, the ones that carry most weight are: national press including Publico, Expresso, Jornal de Noticias, Observador; city guides such as Time Out Lisboa and Time Out Porto; official tourism sources such as VisitPortugal and regional tourism sites; sector associations and local bodies.

The path to appearing in these outlets is sending a concrete and relevant pitch to the journalist or editor, not paying for mentions. Be wary of paid proposals to "get you into the list".

Social media

AI also reads social media, especially when it is the first source where updated information about a brand appears. LinkedIn carries more weight for B2B services; Instagram and Facebook for consumer services.

• The bio on every account uses the same sentence as the website and the Google Business Profile.
• The company name is written exactly the same on every account.
• Old inactive accounts are updated or closed; they are where the most contradictory information tends to appear.

How measurement works with MessGEO

Measurement is what distinguishes GEO Advertisement from simply "improving the website". Without measuring, it is not possible to know whether the work is having an effect, and there is no way to show the client where they started and where they are now. The technical details of the score are on the GEO analysis page.

The measurement cycle works like this:

1. Prompt selection: at the start of the engagement we define together the questions the brand's customer would ask an AI tool, close to a purchase intent: "physiotherapy clinic in central Porto", "accountant for freelancers in Lisbon", "steak restaurant in Cascais". We typically test 10 to 20 prompts per cycle.
2. Measurement on three AI surfaces: we ask each prompt to ChatGPT, Gemini and Perplexity, in European Portuguese and in English when relevant. We record whether the brand appears and what is said.
3. Appearance score: we calculate the percentage of prompts in which the brand appeared, broken down by tool and language. This number is the MessGEO score for the month.
4. Competitor analysis: we also record which brands AI mentions in the answers where our brand did not appear. This shows which competitors are already better prepared.
5. Monthly report: the month's score is compared to the previous month and to the starting point. We identify which source had the most impact and what to do next.

AI tool responses vary between sessions. A single result is not representative; that is why we measure throughout a cycle and calculate an average.

For which businesses

GEO Advertisement is most useful for a business when the customer researches before deciding. In Portugal, it makes the most difference for:

• Clinics and health services: the customer researches a lot before booking; trust is decisive.
• Restaurants, accommodation and tourism: two audiences that ask in Portuguese and in English.
• Beauty and personal care: businesses where the portfolio and reviews are checked before booking.
• Professional services: law, accountancy, real estate, consulting.
• B2B companies: buyers who research in English and on LinkedIn before making contact.

Why Messagency

• We are in Portugal. Our base is in Porto. Our team is made up of digital nomads, so all our meetings are held in English; content for your customers is written in European Portuguese.
• We measure with our own tool. MessGEO was built by us, to measure exactly what we sell. We present results, not estimates.
• We are honest about what is possible. We do not make promises that no serious GEO work can keep. We promise method, measurement and transparency.
• We know the Portuguese market. We know how the Portuguese search, which sources AI reads in Portugal and what distinguishes European Portuguese from Brazilian Portuguese in the context of AI search.
• Fixed and clear price. After the free 30-minute call you receive a written plan with a fixed price; you know the cost before we start.