Sean Ellis

Ellis ran growth at a string of breakouts — LogMeIn, Eventbrite, and Dropbox in its earliest days — and kept noticing that the job he did had no name, so in 2010 he gave it one: growth hacking. Through his GrowthHackers community he popularized two ideas that fit together like lock and key: the north star metric as the number a growth team exists to move, and the 40% survey as the test of whether you've earned the right to move it.

Ellis coined the term 'growth hacking' and then spent a career giving it substance. He ran growth at Dropbox and LogMeIn during their breakout years, invented the 40% product-market-fit survey ('how disappointed would you be if this product disappeared?') that remains the standard PMF instrument, and co-wrote Hacking Growth, the movement's textbook. The North Star Metric discipline he popularized — one number that captures delivered customer value, with a tree of input metrics beneath it — is his answer to growth teams optimizing themselves into vanity.