Microsoft's AI revenue is 70% dependent on OpenAI

Microsoft generated $24.1 billion in AI revenue through OpenAI in the fiscal year ending in June, about 70% of its total AI business, according to a Bloomberg analysis. The dependency comes despite Microsoft's own push to build out Azure AI.

Why it matters: This scale of dependency helps explain why Microsoft has recently championed open-weight models and pushed back against proprietary lock-in, despite its history of vendor lock-in strategies — it's hedging against over-reliance on a single partner. It also shows how much of the hyperscaler 'AI boom' revenue narrative still traces back to a handful of frontier labs rather than broad enterprise adoption.