Rank, Link Building and Google Analytics

This week we learned about improving your rank by building links from other sites and google analytics. Google analytics was a lot of fun. I am better at finding an answer than I am at coming up a with a theory or assumption. I guess your assumptions have more substance when you use analytics. I would assume the information gets clearer the more data you can analyze. Although it was fun I think it would drive we crazy looking at every possible piece of information. How helpful could the information be at start up? Would it be more beneficial because you could see initial reactions? I hadn't realized how much goes into building a site. I understand why there are so many companies out there that charge to build your site.