Microsoft CEO Satya Nadella disclosed during Q3 FY2026 earnings that M365 Copilot now has 20 million paid enterprise seats, with the count of companies purchasing 50,000+ seats having quadrupled, and Accenture signing for 740,000+ seats—the largest Copilot deal to date. Copilot queries per user grew nearly 20% quarter-over-quarter, with weekly engagement now matching Outlook, which Nadella called "a daily habit of intense usage." At 20 million seats, the product implies roughly a $7.2 billion annual run rate, making it one of the fastest-growing enterprise software products ever. The milestone, combined with the separately reported $37 billion AI revenue run rate, underscores how rapidly AI is shifting from pilot to core workflow in large enterprises.