Anthropic's IPO filing with the SEC on Monday, October 26, reveals that more than half of its enterprise customers spending at least $100,000 annually now utilize both the Claude Platform and a first-party application like Claude Code or Cowork. This cross-selling strategy, which the company attributes to driving significant usage expansion and a net revenue retention of approximately 900% as of Q3, is making enterprise customers stickier, a playbook reminiscent of Amazon's AWS ecosystem. The S-1 filing also notes that as of September 30, Anthropic had over 11,900 customers spending at least $100,000, more than 1,900 spending upwards of $1 million, and about 250 spending $10 million or more annually.