The purpose of this post is not to tell you how to improve your eCommerce conversion rates. It is to tell you why you should monitor your conversion rates so you can then try to improve your conversion rates.
With Google Analytics, you can track your website, mobile, and Google AdWords activity as well as your Google Display Network and Analytics ads. You can also analyze your site based on which landing pages, products, and ads have the most impact. Here are my blog posts relating to maximising the impact of Analytics on your website.