A new generation of megabrands like Facebook, Dropbox, Airbnb, and Twitter haven’t spent a dime on traditional marketing. No press releases, no TV commercials, no billboards. Instead, they rely on a new strategy—growth hacking—to reach many more people despite modest marketing budgets. Growth hackers have thrown out the old playbook and replaced it with tools that are testable, trackable, and scalable. They believe that products and businesses should be modified repeatedly until they’re primed to generate explosive reactions.

Bestselling author Ryan Holiday, the acclaimed marketing guru for American Apparel and many bestselling authors and multiplatinum musicians, explains the new rules and provides valuable examples and case studies for aspiring growth hackers. Whether you work for a tiny start-up or a Fortune 500 giant, if you’re responsible for building awareness and buzz for a product or service, this is your road map.

Lesson 1: Marketing has changed, especially for startups.

• Back in the day when Apple started, they would follow a simple mantra: Build a great product, and then get it in front of as many eyeballs as possible. That worked in the 70s and 80s, but today, not so much. The world has become so noisy, that even the best products go unnoticed, if not marketed well. This is why startups focus on growth hacking, a technology-based approach where marketing mechanisms are built into the product itself. It’s cheap, it’s scalable and done right, it works incredibly well. Growth hacking is what got Facebook a billion users, Instagram 400 million, Dropbox 300 million, and on and on goes the list. Instead of orchestrating a perfect launch with a big hype, startups get their product out as fast as possible. It doesn’t matter if version 1 is bad, since the whole point is to make version 2 better. Once the product is out, startups measure and track every bit of data they can, in order to then improve the product to a point where users can’t help but share it all over the place. This approach dissolves the line between marketing and product development and usually relies on the power of the internet.

Lesson 2: Target a small group of early adopters first.

• So how can you growth hack the heck out of your own product? Simple: Target the right people. It might sound obvious, but the general approach most people and companies take to marketing is to try to sell to everybody. However, this leads to a lot less sales, a lot more sales to the wrong kind of customer, and eventually, horrible feedback. Even if you manage to sell a bunch of lawn mowers to people who live in apartments in the city, what could they possibly tell you that’ll help improve your product? Nothing! Instead, just target a very small, but specific group of people who are a perfect fit. For Dropbox, they knew Digg had exactly the right kind of crowd for their service. So when Drew Houston recorded a demo video to show how Dropbox works, he inserted a bunch of easter eggs, which only the Digg community would recognize. Within 24 hours the video had 10,000 Diggs (a like on that platform) and drove hundreds of thousands of people to their site, signing up for the private beta. Only by making access to their product exclusive to their perfect target customers and catering specifically to their needs did they manage to hit critical mass for the product to get traction. So how powerful is growth hacking? Dropbox’s video blew up their waiting list from 5,000 to 75,000 people – in one night.

Lesson 3: Make your product go viral by letting customers market it for you.

• But even with that initial traction you might not make it. Eventually, your product will have to be everywhere. And this is where the buzzword of the 21st century comes in. Viral. How do you get those early adopters to spread the word to all of their peers? Ryan has 2 dead simple tips: Make it shareable. Tell them to share! By simply giving people an incentive and then telling them to do what’s necessary to get that incentive, your customers will work wonders for you. To stick with Dropbox, they give you a variety of options to get more space after signing up, one being to invite friends. Is getting 1 GB of free space worth sending a few emails? It would seem so, given their success. Your incentive can also be financial, for example Appsumo gives you $10 in referral credit every time someone purchases through your link, which means you can buy awesome software and apps for free, as long as you’re sharing. Growth hacking requires you to be creative, so in no way is this limited to digital products. Apple turned every single one of their customers into a walking billboard, simply by coloring their headphones in white and putting a lot of focus on them in ads. Think of creative ways to share and then actually ask people to do it and your product will fly.