Growth Hacking 101, by @yongfook
Adam Rifkin stashed this in Growth Hacks!
In about 20 slides yongfook gives a good introduction to many growth hacking concepts.
I can summarize them as:
1. Create worthwhile content that people will want to share.
2. Encourage people to share.
3. Optimize your landing pages so people know what to do when they get there.