Which sources do AI assistants read before recommending a business?

On 10 July 2025, Meta flipped a switch without a press conference: public content from Instagram professional accounts - photos, videos, carousels, reels - became indexable by Google and other search engines, by default. One new line in the privacy settings, a quiet announcement, and the trade press moved on.

Thirteen months later, we can measure the effect. On 6 August 2026 we asked the AI assistants - ChatGPT, Gemini and Perplexity, the programs that answer in plain language - 1,242 buyer questions across Brazil, covering 207 trade×city combinations. The most cited source in their answers is not a directory and not a review site: it is instagram.com, with 302 citations, ahead of every national directory. The answer to the question in the title fits in one sentence: AI assistants read whatever their market writes, and every market writes in a different place.

What exactly did we measure?

Our three studies follow the same public methodology: questions a customer actually asks - “who is the best dentist in Curitiba?” - put to all three assistants via API, answers archived, sources counted. Three markets, three dated snapshots. Brazil, 6 August 2026: instagram.com first (302 citations), ahead of the services platform ohub.com.br (201) and reddit.com (190). United Kingdom, 31 July 2026: reddit.com dominates everything (628 citations across 1,464 answers), far ahead of Checkatrade and ThreeBestRated. France, 30 July 2026: directories rule - threebestrated.fr (222), petitfute.com, starofservice.com - and no social network at the top.

Three markets, three infrastructures of recommendation: the Instagram storefront in Brazil, the Reddit conversation in the UK, the directory in France.

Why Instagram in Brazil - and why now?

Brazil is Instagram's third-largest market in the world - roughly 154 million accounts as of October 2025 - and a striking share of its small businesses run their main storefront there: the bio serves as the website, stories as opening hours, direct messages as the phone line. As long as Instagram stayed closed to search crawlers, all of that content was invisible to machines. The 10 July 2025 setting reversed it: what Brazilian commerce had been writing for years became readable - therefore read, therefore cited. One honest caveat: our measurement establishes the correlation, not proof of causation. But the mechanism is as simple as it gets - an assistant can only cite what it can read.

The United Kingdom tells the same story down a different road. In early 2024, Google signed a licensing deal with Reddit - around 60 million dollars a year, according to the financial press - to read its conversations. Measured on our side in late July 2026: Reddit is the number one source behind British local recommendations, cited four times more than the first directory. There too, a platform decision redrew who gets recommended - without any of the businesses involved changing a thing about their online presence.

What does this change for your visibility?

Take the measure of the shift. The Pew Research Center documented it in July 2025: when an AI summary sits at the top of the results, people click on links almost half as often. Visibility is no longer decided only on the results page: it is decided in the corpus - the set of sources the machine reads before it answers. Being present in your market's corpus is becoming a condition of commercial existence. And that corpus is not global: it is local, language by language, platform by platform. That is what AEO is about (Answer Engine Optimization: existing in assistants' answers, not just in lists of links).

What should you do tomorrow morning?

• In Brazil: treat your Instagram profile as a data sheet, not a photo album. Public professional account, trade and city spelled out in the bio - and check that search-engine indexing is switched on in the settings: it has been the default since July 2025, but it takes one tap to turn off.
• In the UK: read the Reddit threads where your trade gets discussed. You cannot buy your way in, and disguised self-praise gets spotted fast - but answering usefully, under your real name, in your own field means writing in the source the AIs read most.
• In France: directories remain the raw material - ThreeBestRated, PagesJaunes, your sector's review platforms. A consistent listing everywhere beats a brilliant listing in one place.
• Everywhere: measure before you invest. Our free audit queries the assistants in 60 seconds, no account, and shows who gets cited instead of you - and from which sources.

One last number to keep a cool head: across all our measurements, the three assistants agree with each other on only 2 to 3% of the names they cite. The ground moves and snapshots age fast - which is exactly why we date them. What this August shows is the direction: platforms decide what the machines read, and the machines decide who exists in the answer. Better to know, market by market, where your name is being written.