Growth Loops

Growth hacking, the term this often gets grouped with, is a mindset: fast, scrappy experiments to find what moves a metric. A growth loop is a specific mechanism, and unlike a funnel, it doesn't end. A funnel is linear: traffic goes in, customers come out the other end, and you need to keep pouring in new traffic to get more customers. A loop is circular: existing users generate the input (referrals, content, data) that produces new users, who in turn generate more input. Common loop types: viral loops (a user invites others to use the product with them, like Calendly links exposing the tool to every person scheduled with), content loops (user-generated content gets indexed by search engines and pulls in new users who then generate more content, like Pinterest pins or Stack Overflow answers), and data loops (more usage improves the product for everyone, like Waze getting more accurate as more drivers report traffic). The test for whether you have a real loop: if you stopped all paid acquisition and marketing effort today, would the user base still grow, even slowly, from the mechanism alone? If growth stops the moment you stop spending, you have a funnel with a paid channel at the top, not a loop. Most early-stage products don't have a loop yet and rely on manual acquisition, that's normal, but it's worth designing one deliberately rather than assuming virality will emerge on its own.

Calendly grows through a loop: every person who books a meeting through a Calendly link sees the product and can sign up themselves, with no ad spend required. The more meetings get booked, the more new users the loop produces.