u/holliwilliam

We track AI brand visibility, so we have a lot of stored responses. Wanted to answer something basic: when an AI answers a question, how many brands does it actually name?

234,000+ responses, March 1 to July 13, 2026, five engines.

Brand mentions per response (last 14 days in July)

• ChatGPT: 4.5
• Google AI Overview: 3.5
• Gemini: 3.5
• Google AI Mode: 3.2
• Perplexity: 2.7

Count each brand only once per answer, and it tightens to 2.2–3.3. So engines repeat themselves 1.2x to 1.4x.

Two things stood out:

Every engine is down since March. True whether you count every mention or each brand once, so it's not a repetition artifact.

AI Mode is wildly unstable. Day-to-day swings are 31% of its own average, vs 9% for ChatGPT. It went from 8.8 mentions per response in early May to 2.6 six weeks later. If you spot-check visibility there weekly, you're mostly reading noise.

Method: a "mention" counts every occurrence (Nike named 3x in one answer = 3); the distinct count treats it as 1. Same responses for both. Worth noting these are prompts our customers chose to track rather than a random sample of AI queries, so I'd trust the relative comparisons and trend direction over the absolute numbers.

Charts and full methodology: https://vercite.io/research/engine-personalities

Happy to get into how anything was counted.

Quick disclosure up front: I work on an AI-visibility tracker (Vercite), and this is our data. Link's at the bottom – free to read. Posting here because the findings are genuinely useful for anyone working with AI visibility.

We looked at 5.31 million citations – every source link returned across ChatGPT, Perplexity, Gemini, Google AI Overview, and Google AI Mode – and classified 158,847 domains to see who each engine actually pulls from.

The headline for this sub: ChatGPT's single most-cited website is reddit.com. Not Wikipedia, not a news outlet. Reddit (most of us already know that).

But the bigger pattern is that each engine has a different "home platform":

• ChatGPT → Reddit
• Perplexity → YouTube
• Google AI Mode → YouTube (its #1 source overall)
• Google AI Overview → leans on both Reddit and YouTube
• Gemini → barely any of them (1.4% combined)

A few other things that stood out:

• The 5 engines agree on almost nothing. Pooling each engine's top-100 sources gives 253 distinct domains, and only 23 (9%) are cited by all five. More than half are cited by just one engine and no other. There is no single "AI-friendly" source list.
• Concentration varies wildly. Google AI Mode pulls half its citations from just 71 domains – a tiny club. ChatGPT spreads the same half across 712. AI Mode is winner-takes-all; ChatGPT rewards a long tail.
• Google's AI mostly cites Google. When AI Overview cites a google.com page, 79% of the time it's pointing back to its own Search results. 8.5% of everything it cites is a Google property.

Methodology / caveats (being upfront):

• Real citations from tracked prompts across all five engines, not a one-off lab test.
• We classified all 158,847 domains by source type (forum, news, official, brand-owned, etc.) rather than by industry, so the patterns reflect how each engine sources, not what any one set of prompts was about.

For those tracking AI visibility across engines: are you seeing the same Reddit/YouTube split, and are you optimizing per-engine or still treating "AI" as one channel?

Full write-up with all the charts: https://vercite.io/research/citation-landscape