What it is
Sensor Tower’s State of AI 2026 (released June): ChatGPT booked ~$1.3B in mobile revenue in Q1 2026 — more than 5x the combined total of the rest of the top 10 — and in May became the fastest app ever to cross 1 billion MAU. But the same report shows ChatGPT’s True Audience share slipped below 50% for the first time in March: Gemini (~662M MAU), Claude (~245M), Grok, DeepSeek and Doubao all grew; ChatGPT, DeepSeek and Gemini still account for ~90% of time spent.
Why it matters to you
Two signals, far more important than “ChatGPT makes money”:
- AI Q&A is now a billion-user mainstream entry point, and still growing. Your customers are increasingly using AI to find answers and do research — GEO isn’t a future tense, it’s the present.
- The market is going multipolar. Optimizing your content “for ChatGPT” is no longer enough. Gemini, Claude, Grok and Perplexity each have different sourcing logic and indexes — GEO has to span multiple mainstream engines, or you’re only visible on one.
Should you act now
First, be clear what this data is: it’s mobile-app usage and revenue, not a direct measure of whether your pages get cited. Don’t read MAU growth as “you’ll be cited more” — its value is confirming the market reality and urgency.
What you actually act on is your cross-engine GEO health. How each engine actually picks sources, where they differ, and which “gates” you need to clear — we break it down here: How every AI platform picks citations (the 5 engines, mechanism by mechanism).