Generative AI (genAI) has become a media category unto itself. Large language models (LLMs) like ChatGPT are growing faster than anything else on the web, spending aggressively, and attracting a user base that continues to diversify. But while OpenAI is generally hailed as the kingpin in the space, the reality is a bit more nuanced. The data shows a malleable, multi-platform audience with brand preferences that aren’t as sticky as they may seem—and major players that are adopting very different strategies to reach them.

AI Assistants were the fastest-growing web category of 2025, with traffic increasing 86% YoY, according to Sensor Tower data. Even as nearly every major web category declines in visits—including Browsers & Search Engines (-7%), Education & Jobs (-13%) and Email (-16%)—AI Assistants recorded 101% increase in time spent, ranking among the web's fastest-growing categories. ChatGPT also became the sixth-most-visited website globally. This shouldn’t be seen as a trend anymore; it’s the new state of affairs.

Outbound to Claude: Shifting allegiances among AI users

Sensor Tower traffic flow data shows audiences move fluidly across AI assistant sites, rather than locking themselves into one favored LLM. For instance, from April to May of 2026, ChatGPT users flowed to Claude at nearly 50% month-over-month growth. Over the past six months (as of writing), Claude visits made up 2.1% of ChatGPT’s outbound traffic. Over the past thirty days, that share has grown to 3.2%—making Claude.ai the fifth most popular site users visit after leaving ChatGPT.com.

To dig further into this trend, we can look at audience overlap for the two brands. Users who have the ChatGPT app downloaded are 2.37 times more likely to use Claude than the general population. A full 6.4% of ChatGPT app users also have Claude on their phones.

Beyond the tech bro: AI’s expanding audience

Audience demographics are also shifting in other ways, as adoption of AI Assistants continues to accelerate into the mainstream. The ChatGPT user base, for example, is rapidly evolving beyond the persona of the typical early adopter—often male, often in tech. Sensor Tower data shows that popularity with World Travelers is up 11% over the last six months, and is also on the rise for Sneakerheads (+7%), Gamblers (+7%), Gig Workers (+6%), and Frequent Flyers (+6%). Job & Education and Software are still the leading ad categories ChatGPT users are exposed to, but that field is diversifying as well.

How the category spends, and where OpenAI diverges

But, which ad strategies do top AI Assistants actually use to reach this varied spread of consumers? Overall, genAI ad spend is up 50% in the last six months, per Sensor Tower data, and budget within the space is generally very diversified. The top three channels by spend for the GenAI category (Instagram, Facebook, and YouTube) only account for 49% of ad budget, while pulling in 62% of impressions. ChatGPT strays from the crowd here with significant investment on linear TV (17% vs. a category average of 8%) and under-indexes on LinkedIn (2% vs. 13%). It seems the OpenAI heavy-hitter is making a mass market play, while competitors lean more heavily into the professional crowd.

In 2026, understanding genAI takes more than glancing at the downloads charts. Sensor Tower gives you the full picture—audience behavior, traffic flows, ad strategy, and more—across the entire digital ecosystem.

Want more insights on AI’s impact across the net? Download State of Web 2026.