Growth hacking is a marketing technique developed by technology startups which uses creativity, analytical thinking, and social metrics to sell products and gain exposure. It can be seen as part of the online marketing ecosystem, as in many cases Growth Hackers are simply good at using techniques such as search engine optimization, website analytics, content marketing and A/B testing which are already mainstream. Growth hackers focus on low-cost and innovative alternatives to traditional marketing, e.g. utilizing social media and viral marketing instead of buying advertising through more traditional media such as radio, newspaper, and television. Growth hacking is particularly important for startups, as it allows for a "lean" launch that focuses on "growth first, budgets second." Facebook, Twitter, LinkedIn, AirBnB and Dropbox are all companies that use growth hacking techniques.
Sean Ellis coined the term "growth hacker" in 2010. In the blog post, he defined a growth hacker as "a person whose true north is growth. Everything they do is scrutinized by its potential impact on scalable growth." Andrew Chen introduced the term to a wider audience in a blog post titled, "Growth Hacker is the new VP Marketing" in which he defined the term and used the booking agency AirBnB's integration of Craigslist as an example. He wrote that growth hackers "are a hybrid of marketer and coder, one who looks at the traditional question of 'How do I get customers for my product?' and answers with A/B tests, landing pages, viral factor, email deliverability, and Open Graph." In 2012, Aaron Ginn defined a growth hacker on TechCrunch as a "mindset of data, creativity, and curiosity."
The most popular deck ever created on growth hacking is "Growth Hacking or: Lean Marketing for Startups" by Mattan Griffel. In it, Griffel defines growth hacking as "a set of tactics and best practices for dealing with the problems of user growth." 
Also in 2013 a resource known as Growth Hacker TV interviews top growth hackers at companies involved with the early movements such as Dropbox, LinkedIn, Expedia, Twitter, and Facebook.
In late 2013, growth hacking also found its way into the Asian entrepreneurship scene. The leading resource for growth hacking in the region is Growth Hacking Asia, which was launched with the goal to increase the success rate of Asian start-ups.
Fast Company defined the problem facing most startups as 1) they don't have the money and 2) they don't have a traditional marketing background. To combat this lack of money and experience, growth hackers approach marketing with a focus on innovation, scalability, and user connectivity. Growth hacking does not, however, separate product design and product effectiveness from marketing. Growth hackers build the product's potential growth, including user acquisition, on-boarding, monetization, retention, and virality, into the product itself. Fast Company used Twitter "Suggested Users List" as example: "This was Twitter's real secret: It built marketing into the product rather than building infrastructure to do a lot of marketing."
The heart of growth hacking is the relentless focus on growth as the only metric that truly matters. Mark Zuckerberg, best known of the 5 co-founders of Facebook, is said to have had this mindset while growing Facebook. While the exact methods vary from company to company and from one industry to the next, the common denominator is always growth. Companies that have successfully "growth hacked" usually have a viral loop naturally built in to their onboarding process. New customers typically hear about the product or service through their network and by using the product or service, share it with their connections in turn. This loop of awareness, use, and sharing can result in exponential growth for the company.
Besides Twitter, Facebook, Dropbox, Pinterest, YouTube, Groupon, Udemy, and Instagram are all companies that used and still use growth hacking techniques to build brands and improve profits.
An early example of "growth hacking" was Hotmail's inclusion of "PS I Love You" with a link for others to get the free online mail service. Another example was the offer of more storage by Dropbox to users who referred their friends.
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