AI search source study
Which Sources AI Assistants Cite for European AI Agency Recommendations (August 2026)
Most of the 52,762 sources ChatGPT and Perplexity cited in 4,880 answers about European AI agencies were websites, not directories: 17.2% were sites of agencies in the AIAgencies.eu register and 63.2% other websites, mostly firms outside it. B2B directories were 10.0%, social platforms 4.3% and forums 0.1%. Counted from each answer's own source list, collected August 20–21, 2026.
This study started as a question about the directory itself: when a buyer asks ChatGPT or Perplexity for an AI agency in Europe, where does the answer come from? Much of the AI-search advice sold to agencies assumes the assistants lean on review sites and forums. In this category they mostly do not. They read firms' own websites first, then directories and LinkedIn, and almost never Reddit. The two assistants also read very differently, one leaning far more on agency websites and the other on directories, so advice written for one rarely transfers to the other. Every figure below is a frequency across thousands of answers, not a ranking, and none of them names an agency.
Intro by Gabor Kiss, curator · How we rank
- Answers measured
- 4,880
- Sources cited
- 52,762
- Buyer questions
- 1,310
- Answers collected
Where the citations point
Cited Sources by Type
Every source ChatGPT and Perplexity returned with an answer, typed by its domain.
| Source type | Citations | Share |
|---|---|---|
| Other websites | 33,331 | 63.2% |
| Agency websites in the register | 9,054 | 17.2% |
| B2B directories | 5,287 | 10.0% |
| Social platforms | 2,281 | 4.3% |
| AIAgencies.eu (this site) | 1,943 | 3.7% |
| Public bodies and standards | 794 | 1.5% |
| Trade press and blogs | 36 | 0.1% |
| Forums and review sites | 36 | 0.1% |
"Other websites" are sites on none of the lists: not a directory, social platform, forum, publication, public body or agency in the register. At this sweep they are mostly firms that are not in the register. Shares add up to 100 percent. One answer usually cites several types, so answer counts overlap.
“80.3% of the 52,762 sources ChatGPT and Perplexity cited when recommending European AI agencies were agency and other websites; B2B directories were 10.0% and forums 0.1% (AIAgencies.eu AI search source study, August 2026).” https:/
/ www. aiagencies. eu/ statistics# source- types
Per assistant
ChatGPT and Perplexity Cite Differently
Share of each assistant's own citations. Both answered the same questions the same number of times.
| Source type | ChatGPT | Perplexity |
|---|---|---|
| Other websites | 58.6% | 65.1% |
| Agency websites in the register | 37.3% | 8.9% |
| B2B directories | 1.3% | 13.6% |
| Social platforms | 0.5% | 5.9% |
| AIAgencies.eu (this site) | 0.7% | 4.9% |
| Public bodies and standards | 1.6% | 1.5% |
| Trade press and blogs | 0.0% | 0.1% |
| Forums and review sites | 0.0% | 0.1% |
Sources returned per answer: ChatGPT 6.3, Perplexity 15.3.
“ChatGPT drew 37.3% of its citations from websites of agencies in the AIAgencies.eu register and 1.3% from B2B directories; Perplexity drew 8.9% and 13.6%, answering the same European AI agency questions (AIAgencies.eu AI search source study, August 2026).” https:/
/ www. aiagencies. eu/ statistics# by- assistant
Named sources
The Most-Cited Domains Other Than Agency Websites
Directories, social platforms, public bodies, trade press and forums, by name. Agency websites, listed or not, count only in the totals above: this study names no agency.
| Domain | Citations |
|---|---|
| linkedin.comSocial platforms | 2,218 |
| clutch.coB2B directories | 1,908 |
| sortlist.comB2B directories | 889 |
| themanifest.comB2B directories | 596 |
| f6s.comB2B directories | 495 |
| designrush.comB2B directories | 387 |
| techbehemoths.comB2B directories | 160 |
| digital-strategy.ec.europa.euPublic bodies and standards | 150 |
| ensun.ioB2B directories | 141 |
| interoperable-europe.ec.europa.euPublic bodies and standards | 97 |
| aiautomationdb.comB2B directories | 86 |
| agencies.semrush.comB2B directories | 82 |
“linkedin.com (2,218 citations) and clutch.co (1,908) were the most-cited sources other than agency websites in 52,762 AI assistant citations for European AI agency questions (AIAgencies.eu AI search source study, August 2026).” https:/
/ www. aiagencies. eu/ statistics# domains
Reference set
The Register These Answers Were Matched Against
Firm names in each answer were matched to the AIAgencies.eu register, the curated list of European AI agencies this site reviews. The answers are from August 2026; the register below is as of , recomputed on every build.
- Reviewed agencies
- 319
- Countries
- 23
- Carry an hourly rate range
- 150
- Disclose team size
- 293
“ChatGPT and Perplexity named 7,591 distinct firm names in answers about European AI agencies; 304 were agencies already listed on AIAgencies.eu when the answers were collected (AIAgencies.eu AI search source study, August 2026).” https:/
/ www. aiagencies. eu/ statistics# register
How this was measured
Method and Limits
What was asked. 1,310 distinct buyer questions: up to three phrasings for every city, country, service and industry market the directory publishes, plus two general questions. Each market was asked 5 to 10 times per assistant, spread across its phrasings. 4,880 answers in total, collected August 20–21, 2026. The questions never name AIAgencies.eu.
Which assistants. ChatGPT (gpt-5.6-terra) and Perplexity (perplexity/sonar), called through their APIs with web search on. Claude, Gemini and Google AI Overviews were not measured in this sweep.
What counts as a citation. The sources the API returns with each answer, never links written in the answer text. For Perplexity that is the numbered search-result list its app shows as the answer's sources. One citation is one distinct source URL in one answer: a URL an answer lists twice counts once. Shares are of all citations and add up to 100 percent. Answers citing a type are counted once per answer, so those counts overlap across types.
How sources are typed. Each cited domain is typed by fixed host lists (directories, social platforms, forums, trade press, public bodies) and by matching it to the websites of agencies in the register as of September 28, 2026. "Other websites" is mostly firms that are not in the register. AIAgencies.eu is counted like any other domain, in its own row.
Firm names. Firm names are extracted from each answer's text by an extraction model and matched to the register by website or name. Spelling variants of firms outside the register count separately, so the total is an upper bound.
Independence. This page names no agency. Sweep data never changes a listing, score or rank on AIAgencies.eu, and no one can pay to change what these numbers measure. Disclosure: AIAgencies.eu counts its own citations here like any other domain, and it sells a Pro subscription that shows each listed agency its own results from these same sweeps in depth.
Limits. One sweep, two assistants, English-language questions. Assistants vary their answers from run to run, so every figure is a frequency across many answers, not a ranking.
FAQ
Common Questions About What AI Assistants Cite
Mostly websites. Of 52,762 sources ChatGPT and Perplexity cited across 4,880 answers, 63.2% were websites outside every directory, social, press, forum and public-body list, mostly firms that are not in the AIAgencies.eu register, and 17.2% were sites of agencies in the register. B2B directories were 10.0%, social platforms 4.3% and public bodies 1.5%.
No. ChatGPT drew 37.3% of its citations from agency websites in the register and 1.3% from B2B directories; Perplexity drew 8.9% of its citations from agency websites in the register and 13.6% from B2B directories. They also cite at different volumes: ChatGPT returned 6.3 sources per answer and Perplexity returned 15.3 sources per answer. Both answered the same questions the same number of times.
Rarely. Forums and review sites were 0.1% of all citations: 36 of 52,762, appearing in 32 of 4,880 answers. For this category, placing posts on forums reaches a channel the assistants barely read.
clutch.co (1,908 citations), sortlist.com (889 citations), themanifest.com (596 citations), f6s.com (495 citations). Directories as a whole were 10.0% of all sources cited, across 25 directory domains.
1,310 buyer questions covering every city, country, service and industry market AIAgencies.eu publishes were put to ChatGPT and Perplexity through their APIs with web search on, 4,880 answers in total, collected August 20–21, 2026. A citation is a source the API returns with the answer, never a link in the answer text, and each source URL counts once per answer.
No. Agency websites appear only as totals, and every figure is a frequency across many answers, not a ranking. Sweep data never changes a listing, score or rank on AIAgencies.eu. AIAgencies.eu sells a Pro subscription that shows each listed agency its own results from these sweeps in depth; this page publishes only the totals.
Data
Download and Cite
Every table on this page is free to reuse under CC BY 4.0: CSV · JSON. Credit it as “AIAgencies.eu AI search source study, August 2026” and link to www.aiagencies.eu/statistics.
Change log
- Page published: sweep 1 (ChatGPT and Perplexity, August 20–21, 2026) and the register its answers were matched against.