Sean Ellis

In this interview, Sean Ellis — the marketer who coined the term "growth hacking" — breaks down why most companies fail at growth despite being obsessed with testing. Drawing on his time as the first marketer at Dropbox and his work with Eventbrite and Lookout, Ellis explains that growth is a cross-functional discipline, not a marketing trick. He walks through his testing-driven process, the primacy of activation and retention, and the famous "Sean Ellis Test" for measuring product-market fit — the 40% rule that tells a founder whether a business is worth scaling at all.