"A growth hacker is a hacker whose objective is to grow the number of users for a specific product. While lots of people consider user growth to be a marketing function, this assumes that there's only one way to get users (namely, marketing). But this isn't true. [I]t doesn't make sense to place growth hacking within a particular department like marketing or engineering. Instead, it ends up being a cross-functional role."

Source: Mattan Griffel via Growhack.com

Mattan Griffel is entrepreneur, educator and CEO and co-founder of One Month. Griffel is also a partner at GrowHack and teaches at General Assembly, an educational institution for entrepreneurs.