The single number a team agrees best represents delivered value — weekly active teams, completed bookings, documents signed — and against which roadmap decisions are judged.
Without one, every function optimises its own dashboard and the product drifts. It is also the fastest way to kill features that move a vanity metric and nothing else.
We pick a metric that only improves when a user got real value, keep it visible next to the backlog, and state for each planned feature which input to it the work is meant to move.