AARRR (Pirate Metrics)
Dave McClure, 500 Startups (2007)
Maps the full user journey from first touch to advocacy. The most widely adopted framework for growth-stage startups because it forces you to measure every stage of the funnel, not just the top.
How it works
AARRR treats the user journey as a funnel with five sequential stages. You measure each stage independently, then look for the biggest drop-off—that’s where to focus. The framework works because it forces you to confront the full picture: a product with great acquisition but terrible activation is wasting money, and AARRR makes that visible. Most teams discover their biggest leverage point is NOT where they expected.
Components
Acquisition
How do users find you?
Activation
Do users have a great first experience?
Retention
Do users come back?
Revenue
Can you monetize?
How to implement
- Define what each stage means for your product. "Acquisition" for a marketplace means something different than for a SaaS tool.
- Pick 1–2 metrics per stage. Resist the urge to track everything. A single metric per stage is better than five.
- Identify your leakiest stage. Run a cohort analysis to see where the biggest drop-off occurs.
- Focus improvement efforts on that stage for 4–6 weeks before moving on.
- Review monthly. The bottleneck shifts as you improve each stage.
In practice
Dropbox
Used AARRR to discover that referral was their strongest growth lever. This led to the famous "invite a friend, get free space" program that drove exponential growth at near-zero CAC.
Airbnb
Applied AARRR to find that professional photography of listings dramatically improved activation (guests booking) and retention (hosts staying). A single insight across two funnel stages transformed the business.
HubSpot
Used the framework to identify that free tool users who activated within 7 days converted to paid at 3× the rate, leading to their freemium-first go-to-market strategy.
Best for
Growth-stage startups, product teams building their first metrics stack, and anyone who needs a comprehensive view of the user journey from acquisition to advocacy.
When to avoid
Two-sided marketplaces (the funnel is different for each side), platform businesses where growth is non-linear (network effects don’t fit neatly into stages), and very early-stage products where you haven’t found product-market fit yet—at that stage, only retention matters.
Limitations
Linear funnel assumption breaks down for products with non-linear journeys (marketplaces, platforms). Doesn’t explicitly address engagement depth or user happiness beyond NPS.