Startup Success Patterns

The hierarchy of engagement - Sarah Tavel
Fantastic slideshare about the maturation of user engagement as companies mature, with emphasis on connecting the user engagement hierarchy to behavioral models.

16 startup metrics & 16 more startup metrics - Jeff Jordan, Anu Hariharan, Frank Chen, and Preethi Kasireddy
32 core metrics you should be paying attention to, according to Andreesen Horowitz.