What are the most effective growth hacking techniques you have personally tried and tested?

Anyone who calls themselves something fancy like that is probably one of the 99% in the industry that have no idea what they are doing and will make you hemorrhage money. Find a MARKETER with a proven track record and use them to build an empire. If you don't want an empire and, instead, want to make your friends jealous by bragging about "new hires," then hire a "growth hacker" or "assistant of hardcore development" or "rad visualization chairman" or whatever other stupid position all these failing startups get caught on.

Obviously, they do the fundamentals well. Good brand. Good experience. Good word of mouth. Good PR. Etc. Etc. But after my interview with Ryan Graves, the head of Global Operations at Uber (https://www.growthhacker.tv/ryan-graves), it became clear that they are operationally advanced and this is a huge part of their success. I'll explain. Uber isn't just a single startup, it's essentially dozens of startups rolled into one because every time they enter a new city they have to establish themselves from essentially nothing (except whatever brand equity has reached the city ahead of them). This means finding/training drivers, marketing to consumers, and building out local staff to manage operations for that city. This is where Ryan Graves comes in. He has a protocol of everything that must be done, and in what order, and by who, to ensure the best chance of success in a new city. So how has Uber grown so fast? Essentially, they figured out how to grow in one locale and were relentless about refining their launch process to recreate that initial success over and over in new cities. No plan works for every city, and they've had to adapt in many situations, but it is still a driving factor for their success.

For the sake of getting your question answered here it would help to simplify but that aside without firm stats on engagement and sharing it would be difficult to say however with the paid expansion of game like Flappy Bird, Angry Birds I would say viral apps come close to if not over a k-factor of 1.

I'm answering your question assuming that you hope to be able to replicate it's own success in your own mobile app. There are a couple of factors responsible for it's growth that are instructive to anyone building a mobile app. "Leveraging the intimacy and privacy of the mobile phone." We now have an *intimate* relationship with our phone like no other device in the history of technology. Every internet company that started before around 2010 has built their core interactions around "the old web" one which was accessed primarily via a browser on a computer. Companies that start with a clean slate, should be building their interactions around how to do whatever the app is supposed to do while leveraging what is unique to people's relationship to their mobile devices. Photo-sharing has become a core part of the way we communicate now. Snapchat built something that provided an experience that leveraged the feeling of privacy and intimacy that is unique to mobile. "Provided an escape from the "maturity" of other online services." Too many parents, aunts, uncles and other "old people" have encroached into the social networks of teens and young people. As a result, they've had a desire to find places to express themselves in places inaccessible by older generations. An important distinction is that it's not just parents and relatives that young people are trying to avoid, but also employers & colleges who are increasingly using "mature" social networks to review applicants. "Leveraged PR even bad PR" The fact that the app got so much press about it being used to sext was perfect PR for the company, as it essentially reinforced the brand experience that it has today. Essentially, "if it's safe enough to send a sext, it's safe for any kind of communication I want to have." And although the safety and security of Snapchat is actually not as advertised, it still enjoys the reputation of having less impact than any primarily web-based service. Building a successful mobile application is one of the hardest challenges to face designers, programmers and entrepreneurs in the history of writing software. Happy to talk to you if you're considering building a mobile app, about what I've learned about the "table stakes" for success.

Stop thinking you don't have the skills to do something. You can learn anything if you decide to, but assuming up front that you can't (forever) is dangerous. my2cents