Most brands today track AI referral traffic by measuring visits from users clicking links cited in AI responses. But these numbers are often highly underreported.
Referral-based analytics captures only the fraction of AI interactions where a user clicked a link, the platform passed referrer data, and the browser didn't strip it on the way over. AI platforms vary in how much information they pass along when a user clicks a link (most pass very little). And mobile app traffic from ChatGPT and Claude often strips referrer headers entirely, appearing as "Direct." This matters more than it might seem: According to a report by FivePercent, 83% of AI usage worldwide happens in mobile apps, meaning the majority of AI sessions never had a chance of appearing in referral reports to begin with.
Evertune's AI Usage makes that hidden audience visible. It draws from EverPanel, a consumer panel of nearly 25 million real people balanced to reflect the demographics of the internet, and tracks the share of AI platform users who also visit sites in specific consumer categories. In some categories, ChatGPT's AI Usage has already reached 70% of Google's audience size, which can be as high as 10x more than what traditional tracking would show.
AI Usage Has Grown in Every Consumer Category
To understand how AI adoption is playing out across the consumer landscape, we pulled AI Usage data across dozens of categories, from Finance and Health to Travel and Beauty. In every category measured, the overlap between AI platform users and category site visitors has grown substantially over the past two years, and in several categories the numbers are large enough to reframe how brands should be thinking about AI's role in the purchase journey.
Finance is the starkest data point in the entire dataset. Nearly 70% of ChatGPT users in EverPanel also visit Finance sites, the highest overlap recorded across any category. Gemini's overlap with Finance audiences reached 31%, and Claude, which spent most of 2024 in the low single digits, climbed to 19% by February 2026. All three platforms are now reaching Finance audiences at a scale that makes AI a legitimate channel for any brand competing in that category.
Health Conditions tells a similar story. ChatGPT's overlap with people visiting health and medical sites hit 60% by February 2026, up from 32% in April 2024. That's a near-doubling in under two years. When someone asks an AI what medication to ask their doctor about, or which health system is best in their area, the brands that show up in that response have an advantage that no traditional SEO strategy was designed to capture.
Gemini's Audience Overlap Tripled in 18 Months
Twelve months ago, Gemini's audience overlap sat below 10% across nearly every category. By February 2026, it had reached 25-31% depending on the category, with Finance, Event Tickets, Jewelry & Luxury, and Pets all showing Gemini overlap above 28%. That is a 3x increase in audience reach in roughly 18 months.
For brands focused exclusively on ChatGPT visibility, Gemini's trajectory is a warning. The second-largest AI audience in the US is now large enough to represent a material blind spot for brands that aren't tracking their position there. Visibility strategies built around a single platform are already incomplete.
Claude Went from 5% to 19% in Three Months
Claude lagged distantly behind the other models for much of 2024 and 2025 with below 5% AI Usage in most categories. But since November 2025, Claude's overlap index has climbed sharply across categories, reaching 14-19% in Finance, Event Tickets, Nutrition & Fitness, Health Conditions, and Beauty Products & Skincare by February 2026.
Claude went from a rounding error to a meaningful audience platform in roughly three months. Sometimes seen as relevant only in B2B, Claude's AI Usage shows the audience extending well beyond enterprise users.
Referral Traffic Tells You Who Clicked. AI Usage Tells You Who Was Influenced.
The AI Usage data answers a question that often stalls GEO conversations internally: is this audience real, and is it mine? The answer, across Finance, Health, Travel, Luxury, Beauty, Fitness, and E-commerce and other categories, is that more than half of the people who are your customers are also active users of at least one major AI platform. Most of them are using ChatGPT. A growing number are using Gemini. And a fast-moving segment is now using Claude.
Referral traffic tells you who clicked. AI Usage tells you who was influenced. For most brands, the second number is the one that actually matters, and right now it's going unmeasured.
Evertune is the AI marketing platform for Generative Engine Optimization (GEO) that helps brands improve visibility in AI search by analyzing responses at scale and delivering actionable insights. Evertune works with leading brands across all verticals, including Finance, Retail and E-Commerce, Automotive, Pharma, Tech, Travel, Food and Beverage, Entertainment, CPG, and B2B. Founded by early team members of The Trade Desk, Evertune has raised $20M in funding from leading adtech and martech investors. Headquartered in New York City, the company has a growing team of more than 40 employees.
Don't forget to share this post
