1. Retention trumps acquisition
2. Growth favors the agnostic
3. Customer development is cheating
4. Data-informed is better than data-driven
5. Deep growth can’t be hacked
6. Destroy cognitive overhead
7. There is one metric that matters
8. Metrics don’t tell you what to do
9. Growth is not rocket science
10. Language is everything
11. Correlation is good, but causality is better
12. It’s the product, stupid
13. Start a local growth hacking group

By the way, even this article admits that growth hacking is bunk:

You can do things to drive traffic. You can do things to retain users. You can do things to hack growth at a surface level, but deep growth cannot be manipulated. Great products – the ones that are woven into the fabric of our lives and become habits and addictions – tap into something buried within the human psyche. Twitter-esque, Facebook-esque, and LinkedIn-esque growth cannot be hacked. There is something deeper at play.

Brian Chesky of Airbnb paraphrases Paul Graham:

100 users who love you are worth more than a million users who kind of like you.

How to Design for Viral Growth: 

http://pandawhale.com/post/20411/how-to-design-for-viral-growth