Growth hacking is the experimental discipline of using non-obvious, leverage-driven tactics to drive rapid user or revenue growth, coined by Sean Ellis in 2010. It combines marketing, product, engineering, and data, often by exploiting existing platforms, distribution loops, or product mechanics rather than by spending on traditional advertising. It is the experimental, scrappy ancestor of modern growth marketing, and the term has been so over-claimed that the original meaning is nearly buried.
The canonical historical examples define what growth hacking actually was. Hotmail appended "PS: I love you. Get your free email at Hotmail" to every outgoing message in 1996 and went from zero to 12 million users in 18 months. Airbnb ...