Just a very short message to direct you to my article on statistical significance over on the Kissmetrics blog. The emphasis is on intuitive means to understanding the key ideas.
Check Out My Guide to Statistical Significance on Kissmetrics
Fun, example-filled guide, aimed at building intuition
This external article was originally part of my Entreprenerd: Marketing for Programmers book, most of which is available to read for free on jackkinsella.ie
Ways metrics mislead you; how to overcome low reach/low quality score/high CPC etc.
The relevant laws, some growth-hackery tips, and suggestions about good emails to send