Everything you thought you knew about marketing is obsolete.

We can see the incontrovertible evidence right in front of us. A new generation of multibillion dollar brands-Facebook, Twitter, AirBnb, Evernote, and countless others-have been built without spending a dime on traditional marketing techniques. No press releases, no PR firm, no Madison Avenue, no billboards in Times Square.

It wasn't luck that took them from tiny start-ups to massive success. They have a new strategy. It's called Growth Hacking. And it works.

A Growth Hacker is someone who rejects what "marketing" is supposed to be and replaces it only with tools that are testable, trackable, and scalable. Growth Hackers rely on inexpensive tactics like e-mail, pay-per-click ads, blogs, and platform APIs. They chase real results in a field that was dominated by gut instincts for nearly a century. They reject the traditional marketing worship of all things big: big budgets, big campaigns, big opening weekends. Instead, they embrace the opposite: taking a start-up from nothing to something, launching a Kickstarter project, building something that truly spreads.

Growth Hacker Marketing offers both a new mindset and a new set of rules. Bestselling author Ryan Holiday, the former director of marketing for American Apparel, will convince you of the urgency of this awakening. He shows why the game has changed forever and what to do about it-whether you are an aspiring marketer, an entrepreneur, or a Fortune 500 senior executive.