This page collects the numbers people ask about most when they plan for AI search, with the date and source of each one. We only include a figure when we could trace it to the company that published it or to a named study, and we say when a number is a forecast, a correlation or a single study.
How to use this page: quote each figure with its original source and date (links below). If the page saved you time, a link back to it is appreciated. We update it when a source publishes newer numbers; the date at the top shows the last review.
#Key figures at a glance
| Figure | Value | Source and date |
|---|---|---|
| ChatGPT weekly active users | 900 million (and 50 million paying subscribers) | OpenAI, February 2026 |
| Google AI Mode monthly active users | More than 1 billion | Alphabet Q2 2026 earnings remarks, July 2026 |
| Gemini app monthly active users | 1 billion | Google, August 2026 |
| Clicks on a regular result when Google shows an AI summary | 8% of visits, versus 15% without one | Pew Research Center, July 2025 |
| Change in position-one click-through rate when an AI Overview appears | About 58% lower | Ahrefs, 2026 re-run of its 2025 study |
| Share of all website traffic that comes from AI assistants | Between about 0.3% and 1%, depending on the sample | SE Ranking 2026; Conductor 2025 |
| Growth in AI-referred traffic to US retail sites | +393% year over year in Q1 2026 | Adobe, Q1 2026 data |
| Strongest correlate of brand mentions in AI Overviews | Branded web mentions (correlation 0.664) | Ahrefs, 75,000-brand study |
| Chance an assistant gives the same brand list twice | Less than 1 in 100 | SparkToro and Gumshoe study |
#How many people use AI assistants
- ChatGPT has 900 million weekly active users and 50 million paying subscribers, OpenAI said on February 27, 2026, up from the 800 million weekly users it reported in October 2025 (TechCrunch).
- Google's AI Mode has passed 1 billion monthly active users since it expanded globally, Sundar Pichai said in Alphabet's Q2 2026 earnings remarks. He also said AI Mode is adding to the total number of searches rather than only replacing them (Google).
- The Gemini app reached 1 billion monthly active users in August 2026, up from about 400 million in May 2025 and 950 million in July 2026. The count is for the app alone and does not include AI features inside Search (iPhone in Canada).
- A forecast, for context: in February 2024 Gartner predicted that traditional search engine volume would drop 25% by 2026 as people move to AI chatbots and virtual agents (Gartner). It is a prediction, not a measurement, and Google reported all-time-high Search usage in mid-2026, so treat it as a direction of travel rather than a fact about 2026.
What it means: user numbers are not the same as buying questions, but the audience asking assistants is now the size of a major search engine. It is worth knowing what they are told about your category.
#What AI answers do to clicks
- People click less when Google shows an AI summary. Pew Research Center tracked the browsing of 900 US adults in March 2025: users clicked a traditional result in 8% of visits to a results page with an AI summary, against 15% without one. Links inside the summary itself were clicked in about 1% of visits, and people were more likely to end their browsing session after a page with a summary (26% against 16%). 58% of the panel ran at least one search that produced an AI summary that month (Pew Research Center).
- The top result loses more than half its clicks when an AI Overview appears. Ahrefs' 2026 update of its click-through study found the top-ranking page's click-through rate about 58% lower on keywords that show an AI Overview than on comparable keywords without one (Ahrefs press release). The 2025 version of the study found 34.5% (Ahrefs). Ahrefs reports this as a correlation, not proof that AI Overviews alone caused the drop.
What it means: for questions that trigger an AI answer, being named or cited inside the answer matters more than it used to, because fewer people scroll past it.
#How much traffic AI assistants send
- Still a small share of all traffic. Conductor's benchmark of 13,770 domains found 1.08% of all website traffic came from AI referrals between May and September 2025, and ChatGPT sent 87.4% of those referrals (Search Engine Land). SE Ranking measured 0.32% in 2026, up from 0.24% in 2025 and 0.02% in 2024 (SE Ranking). The two numbers differ because the samples and methods differ.
- Growing quickly, and converting better. Adobe reported that traffic from AI sources to US retail sites grew 393% year over year in Q1 2026, and that by March 2026 it converted 42% better than other traffic; a year earlier it had converted 38% worse (Decrypt, citing Adobe).
- Visitor value estimates vary widely. Semrush estimated that the average visitor from an AI search platform is worth 4.4 times an average organic search visitor, measured by conversion rate (Semrush). Other studies put the gap anywhere from about 2 times to more than 20 times, mostly because they measure different sites and industries.
What it means: most sites cannot judge AI visibility from referral traffic alone. Many answers name a brand without sending a click, and some assistants don't pass a referrer, so measure what the answers say as well as the visits you can see. Our article on reading GA4 for AI referrals covers the visits part.
#How buyers use AI to choose
- Most technology buyers now use AI during a purchase, and nearly all of them check it. TrustRadius's 2026 B2B Buying Disconnect report, based on a January 2026 survey of 1,862 technology buyers, found that 63% used AI tools during their purchase journey and 94% of those fact-check the output at least some of the time. Buyers shortlisted 2.7 products on average (MarketScale, on the TrustRadius report).
What it means: a short list is short. If an assistant leaves you off it, you may not get a second look; and because buyers verify, the pages and reviews the assistant cites need to back up what it says.
#What goes with being mentioned and cited
- Mentions across the web correlate with AI visibility more than links do. In Ahrefs' study of 75,000 brands, the factors most correlated with a brand being mentioned in Google's AI Overviews were branded web mentions (0.664), branded anchor text (0.527) and branded search volume (0.392); branded traffic showed a weak correlation (0.274) (Ahrefs). These are correlations, not proof of cause.
- Community and video sites are cited constantly. Semrush ran 325,000 prompts in January and February 2026 and found Reddit was the most-cited domain across ChatGPT Search, Google AI Mode and Perplexity (eMarketer, on the Semrush study). Trackers using other prompt sets rank YouTube and Reddit at the top as well, though the exact shares differ between studies.
- Content changes can measurably shift visibility in controlled tests. The research paper that coined "generative engine optimization" reported visibility gains of up to about 40% in its experimental setup (Aggarwal et al., KDD 2024). Live products change constantly, so treat that as a reason to test, not a promised result.
What it means: your own site is necessary but not sufficient. Reviews, community discussion, comparisons and press that mention you by name are what assistants tend to find and repeat. Our guide to AI citation tracking shows how to see which sources your engines lean on.
#How stable AI answers are
- Recommendation lists almost never repeat exactly. Rand Fishkin (SparkToro) and Patrick O'Donnell (Gumshoe) had volunteers run 12 prompts 2,961 times across ChatGPT, Claude and Google's AI. The chance of getting the same list of brands twice was under 1 in 100, and the same list in the same order appeared less than 0.1% of the time. How often a brand appeared across many runs was much steadier (Search Engine Land). The study was not peer reviewed, and both authors work in the industry.
What it means: a single screenshot of an AI answer proves very little. Track how often you appear across repeated runs and report a range. This is the approach Citeroot takes (how we measure).
#FAQ
How many people use ChatGPT? OpenAI reported 900 million weekly active users in February 2026.
Do AI Overviews reduce clicks? The evidence says yes for the results below them: Pew found people clicked a regular result in 8% of visits when an AI summary appeared, against 15% when none did, and Ahrefs found the top result's click-through rate about 58% lower on keywords with an AI Overview.
How much website traffic comes from ChatGPT and other assistants? Roughly 0.3% to 1% of all traffic in recent studies, with ChatGPT sending most of it. The share is small but growing fast, and it tends to convert well.
What makes an AI assistant mention a brand? No one can say for certain. The strongest published correlation is with how often the brand is mentioned across the web (Ahrefs). Being described consistently and favourably on sites the assistants cite, such as reviews, community threads and comparisons, is the practical lever.
Are AI answers consistent? No. The same prompt rarely returns the same list twice, so measure visibility as a rate over many runs.
#Sources
- OpenAI via TechCrunch, ChatGPT reaches 900M weekly active users, February 27, 2026.
- Google, Q2 2026 earnings call: remarks from our CEO, July 2026.
- iPhone in Canada, Google Gemini app surpasses 1 billion monthly active users, August 12, 2026.
- Gartner, Gartner predicts search engine volume will drop 25% by 2026, February 19, 2024.
- Pew Research Center, Google users are less likely to click on links when an AI summary appears in the results, July 22, 2025.
- Ahrefs, study of AI Overviews and click-through rates (2025 version, with a link to the 2026 update), and the 2026 press release via Business Wire.
- Search Engine Land, report on Conductor's AI referral benchmark.
- SE Ranking, AI traffic grew 16x from 2024 to 2026.
- Decrypt, AI traffic to US retailers jumps 393% in Q1 (Adobe data).
- Semrush, AI search traffic study, 2025.
- MarketScale, 94% of B2B buyers fact-check AI research outputs (TrustRadius 2026 report).
- Ahrefs, An analysis of AI Overview brand visibility factors (75K brands studied).
- eMarketer, chart of the most-cited domains in AI search (Semrush data, March 2026).
- Aggarwal et al., GEO: Generative Engine Optimization, KDD 2024.
- Search Engine Land, AI recommendation lists repeat less than 1% of the time (SparkToro and Gumshoe study).