The Original Growth Hacker
Reveals His Secrets

Sean Ellis

Author of Hacking Growth · Coined "Growth Hacking"
Head of Growth at Dropbox & Eventbrite · LogMeIn founding team

SEP 5 2024

The PMF Test

The Sean Ellis Test: One Question that Changes Everything

"How would you feel if you could no longer use this product?", Ask only active users who've used it 2+ times within the last 2 weeks.

Focus entirely on the "very disappointed" group, they're your must-have users
Ignore "somewhat disappointed", they signal a nice-to-have, not a must-have
40% is a guideline, not a law, culture and category affect the number
It's a leading indicator; retention cohorts are the true final measure
Minimum ~30 responses before treating the score as reliable

Framework

From PMF Signal to Scalable Growth Engine

40%

PMF threshold

min responses

2wk

recency window

Deeply understand who your must-have users are and why before you scale anything
North Star Metric = a unit of must-have value delivered. Not revenue, Amazon uses monthly purchases, Airbnb uses nights booked
Acquisition is the last priority, fix conversion and retention first or ad spend simply won't scale
Blend qualitative (surveys, calls) with quantitative (cohort data, A/B tests), experiments get dramatically better when rooted in customer context

Lookout case study 7% PMF score → repositioned entirely on antivirus + streamlined onboarding to lead with "you're now protected." Score hit 40% in 2 weeks, 60% in 6 months. Became a unicorn.

Deep Dive

Speed to Value: The Activation Obsession

The LogMeIn 10× activation story

95% of signups never completed a single remote control session, the actual product use
CEO froze the entire product roadmap; all of product, engineering, and design shifted to activation only
3 months later: signup-to-usage improved from 5% → 50%
Same acquisition channels that had maxed at $10K/mo now scaled to $1M/mo
80% of new users came through word of mouth after the fix, organic flywheel kicked in

"A problem well stated is a problem half solved.", Kettering (Sean's favourite quote). Most activation problems vanish once the right question is asked.

Two universal conversion levers

1. Increase desire, remind users of the benefit they're about to receive at every step.
2. Reduce friction, ruthlessly cut every step between signup and aha moment.

Ask why they dropped off

LogMeIn had 90% drop at download. After 10+ failed A/B tests, they simply emailed non-downloaders "what happened?" Answer: "seemed too good to be true, I didn't believe it was free." Added a paid-trial option beside free → 300% lift in download rate.

Find your aha moment

Start qualitatively: what's the earliest moment a user genuinely feels value? Then confirm with data, does reaching that moment correlate with long-term retention? If yes, optimise relentlessly for speed to that moment.

Tactics

Mine the Must-Have Cohort

Step 1, Open-ended: "What is the primary benefit you get?" Crowdsource raw language from very-disappointed users
Step 2, Multiple choice: Turn top answers into 4 benefit options; send to a different group of very-disappointed users and force a pick
Step 3, Context: "Why is that benefit important to you?", this unlocks acquisition copy. Xobni users said "I'm drowning in email." That became the ad hook.
Step 4, Alternatives: "What would you use instead?" Must-have users struggle to answer; nice-to-have users name substitutes instantly
Superhuman twist: For somewhat-disappointed users who value the same core benefit, ask what's missing, move them up without diluting the core

Nubank's evolution Uses the Sean Ellis test down to the feature level. New features must hit 50% before public launch. Sean wasn't involved, they adopted it independently.

Contrarian

Growth Myths Sean Ellis Kills

✗ Drive acquisition first to learn fast INSTEAD → ✓ Fix activation and retention first. Pouring traffic into a leaky funnel burns budget without building anything. Acquisition channels won't scale until conversion is efficient.

✗ A referral program creates word of mouth INSTEAD → ✓ Referral programs are an accelerant, not a spark. Dropbox had strong organic sharing before the incentive program launched. It can't fix a product no one talks about.

✗ Revenue should be your North Star Metric INSTEAD → ✓ Measure units of value delivered, nights booked, monthly purchases, weekly rides. Revenue is a byproduct of doing that well. Teams optimising revenue directly tend to shortcut value creation.

✗ 40% PMF score means you're ready to scale INSTEAD → ✓ PMF is only the starting line. You still need to understand who your must-have users are, build the activation loop, and prove retention cohorts, only then does acquisition spend pay off.