With a nearly 80% market share, your site may be one of the tens of millions of sites that uses Google Analytics to track the performance of your website. But what does that mean for you? What metrics should you look at and focus on? The answer is, that depends on your goals.Every website has a different reason for being. The goal of a retail website, for example, is to have visitors buy and complete a checkout purchase. Publishers want to sell ad revenue, likely from ad impressions.