ChatGPT still leads with about 1.1 billion monthly users, but its share fell from just over 50% in January to 46.4% by the end of May. Google’s Gemini follows at 662 million users (27.7% share) and Anthropic’s Claude at 245 million (10.3%). All other assistants—xAI’s Grok, Perplexity, DeepSeek, Meta AI—lag under 5% each. Even as ChatGPT hit a record 1 billion monthly users faster than any app, rivals are nibbling away at its dominance. Sensor Tower’s report shows people are more willing to hop between bots. Gemini benefits from tight integration with Google’s suite, while Claude’s reputation for handling work tasks has boosted its retention close to ChatGPT’s. A spike in ChatGPT uninstalls followed OpenAI’s February defense deal, suggesting trust and brand values sway user choices as much as features. App downloads and spend are climbing but cooling off. In the first half of 2026, users grabbed nearly 2.3 billion AI apps and spent $4.2 billion—up from $1.83 billion in H1 2025. Growth rates have slowed, hinting at market maturation. Asia saw a 3.3% download drop in Q1, driven by China and India, even though it still leads in total installs. North America and Europe outpace Asia in per-user spending, a gap companies will watch when rolling out paid features. On monetization, ChatGPT started testing ads in February. By May, 17% of daily users saw ads, mostly from software, media, and food brands. Its shopping links are steering traffic to retailers like Target and Costco—Amazon’s block on ChatGPT crawlers has kept its referrals flat. Meanwhile, Walmart’s embedded assistant, Spark, is gaining ground on Amazon’s Rufus, and data show that shoppers using on-platform AI spend more time and convert at higher rates.