Much hype and discussion have centered around growth hacking and its various tactics over the past few years, particularly among the tech startup scene. Regardless of some critics' views, numerous success stories have shown that growth hacking, if applied creatively and cleverly, can indeed turbocharge a startup's business growth to staggering heights in a short period of time. The author of this book, an experienced growth hacker himself, shares some of the critical lessons he has learned or witnessed regarding the implementation of growth hacking in key aspects of startup growth, including product market fit, user acquisition, user retention, user engagement, viral marketing, revenue creation, etc. Behind all the U.S. and China startup stories cited in the book lies the growth hacking mindset, i.e. continuously experimenting with new ideas, willingness to fail repeatedly to keep learning, exploring creative hacks to gain insights on user demands, relentlessly tweaking and improving the user experience, a keen sense of human psychology and behavioral tendencies, etc.