Sean Ellis
One of the earliest and most influential growth thinkers and practitioners in Silicon Valley. Coined the term “growth hacking,” invented the ICE prioritisation framework, and developed the PMF survey (the Sean Ellis test). Head of growth at Dropbox and Eventbrite; founding team at LogMeIn (acquired for >$4B); advised Microsoft, Nubank, and others. Author of Hacking Growth (co-authored with Morgan Brown). Created PMFsurvey.com as a free public resource.
Appearances
Key ideas
The Sean Ellis test. Survey active users: “How would you feel if you could no longer use this product?” ≥40% answering “very disappointed” is a leading indicator of PMF. The threshold is a team-alignment tool, not a hard scientific threshold. Cultural differences affect calibration (Nubank uses 50%; some markets warrant lower thresholds).
Ignore somewhat disappointed. The “somewhat disappointed” cohort signals a nice-to-have and risks diluting the product if over-indexed. Superhuman’s refinement: identify somewhat-disappointed users who share the must-have benefit and ask what they additionally need — the way to expand without diluting.
Activation first. Growth sequence is activation → engagement → referral → revenue → acquisition, not the reverse. LogMeIn: 95% of sign-ups never completed the core action; fixing activation 10× improved it and unlocked channels previously capped at $10K/month.
North star = value delivered. The north star metric counts units of the PMF experience delivered in a period, not vanity metrics. Derive it by identifying the must-have benefit through open-ended then forced-choice surveys, then asking why that benefit matters.