The news: OpenAI’s ChatGPT remains the most popular AI service with 1.1 billion unique monthly users, but its market share dropped to 46.4% in May while Gemini climbed to 27.7% and Claude to 10.3%, per Sensor Tower data. ChatGPT’s share has been in steady decline since September 2025 and first fell below 50% in March. 

More critically, a slew of competitors with owned ecosystems are offering what ChatGPT cannot at scale—apps and services that multiply customer touchpoints across search, workspace, operating systems, and retail. Consumers are also switching between AI assistants, mirroring the streaming video market.

Why it’s worth watching: While ChatGPT remains the leading AI provider by a wide margin, its competitors are growing their user bases with AI features and customer touchpoints across a range of owned products and services, showing how AI can transform into an ecosystem play. 

• Gemini sits inside Google Search, Gmail, Docs, Android, Nest, and Chrome.
• Microsoft’s Copilot is woven across Windows, Microsoft 365, Edge, and GitHub.
• Within social media, xAI’s Grok resides natively on X, while Meta AI is threaded through Facebook, Instagram, Messenger, and Ray-Ban Meta glasses.
• Apple’s upcoming Siri AI is expected to run inside camera, messaging, and calendar apps across billions of devices.

AI usage and access are expanding from chatbots to familiar tools, devices, and services, making the technology available beyond opening an app or a website and asking the chatbot a question. 

Implications for marketers: As Gemini, Claude, and others boost their market share, brands face AI’s period of fragmentation through products, services, and online utilities that feature AI interactions at every turn. 

• Marketers should audit how their brands appear when queried across chatbots—a single-platform strategy might not extend across competing services.
• Use AI’s diversification as a springboard to improve audience targeting across models and services by learning which ones your customers are using.
• Track user churn and switching trends, and anticipate where customers are likely to spend most of their time.