Share 'What am I doing wrong? 4,000+ hits 0 sales'

Okay, I know, parts of the hits are just visitors. I can tell, they are interested in one of my document and it is a good thing that I can get about 2,000 people to my website each month just for that. Now, still! I get many hits of people interested in my products, but they don't get bought. At least, not as much as I'd like it to be! So... What's wrong?! My website is here: http://www.m2os...