Growth hacking (also known as ‘growth marketing’) is the use of resource-light and cost-effective digital marketing tactics to help grow and retain an active user base, sell products and gain exposure. Think ‘hacking’ in terms of life hacks – those little shortcuts that make your life easier – rather than nasty bits of code that can ruin your computer and your life.

Growth hacking is most commonly associated with start-ups and small businesses, i.e., those organizations that don’t have a huge amount of cash to spare but need results quickly. However, it’s a scalable concept applicable to any online business looking to maintain the growth and retention of an active user base.

via - Growth hacking - Optimizely