OpenEvidence: Most physicians quietly use this medical AI tool

OpenAI launched ChatGPT for Clinicians in April without licensing NEJM or JAMA. OpenEvidence has both, hit 65% of US physicians across 27 million April clinical encounters, and got repriced from $1B to $12B in 15 months. The binding constraint for frontier labs entering credentialed verticals is content licensing, not model capability, and OpenAI just supplied the revealed-preference proof.