Claim
The scarce capability in product marketing is interpersonal craft — the ability to find a common language for the whole company to talk about the product — not industry knowledge, writing ability, or AI fluency. Those are learnable. The translation layer is not.
Mechanism
Industry knowledge transfers in weeks. AI fluency is table stakes in 2026. Writing skill is abundant. The rarest capacity is synthesizing input from engineering, sales, customer success, and leadership into a single vocabulary everyone uses consistently. Without it, positioning leaks into execution inconsistency regardless of how clean the strategy document is. The PMM earns the seat by reducing the translation cost that everyone else in the company pays.
Conditions
Holds when: the company has multiple stakeholder functions with divergent vocabularies and the PMM is the translation layer.
Fails when: the company is pre-launch with two or three people and the common-language problem has not surfaced yet. Domain expertise reduces translation cost significantly in highly technical markets.
Evidence
"the ability to find a common language for the whole company to talk about the product" — Rory Woodbridge, "Respect the Craft," May 14, 2026
Woodbridge draws the explicit line: "product marketing powered by AI can be one of your most valuable functions" while warning against treating AI as wholesale replacement for interpersonal craft.
Signals
- Sales, CS, and marketing describe the same product feature using the same language unprompted
- Launch messaging sticks without a correction cycle after handoff to other teams
Counter-evidence
Domain expertise reduces translation cost significantly in highly technical markets (DevTools, security, fintech). Some companies hire for domain first and coach craft. Both paths can work depending on market complexity.