Growth management (the discipline behind "growth hacking") is a system of running rapid, measurable experiments across the whole funnel to grow a business metric — not a marketing tactic. Sean Ellis coined "growth hacker" in 2010 for people whose only goal is growth ("a growth hacker is not a marketing Director... their true north is growth"). The practice settled into a repeatable loop of data, ideas, prioritized experiments, and analysis. Dave McClure's AARRR set describes the classic funnel: acquisition, activation, retention, referral, and revenue. Growth loops replace that funnel with a cycle whose output feeds the next round. Teams steer the work with a North Star metric and the input metrics beneath it. The work pays off after product-market fit, where Ellis' 40% test marks the line.
History and core test
- Sean Ellis (2010) — coined growth hacking while at Dropbox; later founded GrowthHackers.
- Product-market fit test — his survey question: "How would you feel if you could no longer use [product]?" ≥ 40% answering "very disappointed" signals PMF. Below that, growth tactics amplify a leaky bucket.
- The discipline matured from hacks into a structured system: data → ideas → prioritized experiments → analysis → repeat.
AARRR vs growth loops
AARRR "pirate metrics" (Dave McClure) — the classic funnel: Acquisition, Activation, Retention, Referral, Revenue. Funnels are linear: customers enter, some convert, the rest leak out.
Growth loops (Brian Balfour / Reforge) — the newer model. A loop is a closed system where the output of one cycle is reinvested as input to the next:
Investment → Action → Output → (reinvested) → Action → ...
Loop types:
- Usage loops — using the product creates more value or inventory (e.g. user-generated content attracting more users).
- Viral loops — one user's usage exposes new users (invites, shared docs, social feeds).
- Paid loops — revenue is reinvested into acquisition (CAC < LTV).
- Sales loops — sales output funds more sales capacity and targeting data.
- Ecosystem loops — partners/plugins extend the product (platform effects).
Implication: model your growth as the loop you can compound, then measure each step of it.
North Star and input metrics
- North Star Metric (NSM) — one metric that best captures the value delivered to customers (e.g. Airbnb nights booked, Spotify time listening). Not revenue itself — a proxy for delivered value that correlates with it.
- Input metrics — the levers under the NSM (signups, activation rate, retention cohorts). Teams own input metrics; the NSM keeps them aligned. The tree of NSM → input metrics is the growth equivalent of an opportunity solution tree.
Experimentation
- High-tempo testing — Sean Ellis' framework: 1-2-3 in the first 4 weeks (1 big idea, 2 must-win tests, 3 days per test cycle) to find the first win fast.
- Standard cadence: ICE-prioritized experiment queue → ship → measure → document → re-rank. Expect most experiments to fail; the value is in the compounding wins.
- Vitamins vs painkillers — growth experiments that only add surface polish ("vitamin") rarely move metrics; experiments that remove real friction ("painkiller") do.
Team structure
- Growth team — a cross-functional pod: PM (or growth lead), data analyst, engineer(s), designer, sometimes a marketer. Often owns its own backlog and even its own engineering pod.
- Where it sits — independent team ("growth squad") targeting the funnel end-to-end, or embedded with product teams. Reed Hastings' famous framing (Growbot at Facebook): growth as a dedicated machine.
- Growth vs marketing — marketing owns awareness and demand channels at the top; growth owns the entire funnel and is accountable to a metric, running product-led experiments, not just campaigns.
When to invest
- Growth work after product-market fit — the 40% test above. Pre-PMF, effort goes to retention and product.
- PLG (product-led growth) — when the product itself is the main acquisition/activation channel (Slack, Figma, Dropbox); growth loops and PLG usually go together.
Growth PM vs core PM
A Growth PM runs short-horizon (weeks) experiments on a business metric anywhere in the funnel, often on a dedicated growth pod. A core PM owns long-term product strategy for a surface. Companies differ on whether growth is a separate pod or a partner discipline to the core PM. Details: Product Management.
See also: Product Management
Sources: Sean Ellis — Find your 40% PMF threshold (startup-marketing.com), Reforge — Growth Loops, Brian Balfour — Why Funnels Fail, Ant Murphy — PM vs PMM vs Growth PM. Verified 2026-10-29.