ChatGPT's global market share has dropped below 50% for the first time, falling to 46.4% by May 2026, according to Sensor Tower's State of AI Report. Despite still leading with over 1.1 billion monthly users, competitors are gaining ground: Gemini holds 27.7% and Claude 10.3%. Claude stands out with a 13% subscription conversion rate, the highest in the industry. The AI app market is maturing — H1 2026 spending is on pace to exceed $4.2 billion, up from $1.83 billion in H1 2025, though growth rates are decelerating. OpenAI is also experimenting with ads, serving them to 17% of daily ChatGPT users by May. In shopping, ChatGPT is driving referral traffic to retailers like Walmart and Target, while Amazon's blocking of ChatGPT crawlers has stalled its own referral traffic.
