Pirate Metrics (AARRR), coined by Dave McClure, organizes a startup’s key metrics into five stages — Acquisition, Activation, Retention, Referral, Revenue — whose initials spell a pirate’s ‘AARRR’. It gives teams a shared map of the customer lifecycle.

By isolating each stage, the framework helps pinpoint the single biggest leak in the growth engine rather than optimizing everything at once.