Once you set up Google Analytics, you’ll gain insight into how people are using your website.
For example, you can see how many users visited a page that sells product A versus a page that sells product B. Or you can determine how many users actually made it to the purchase confirmation page.
Google Analytics can even determine the web traffic source, which is what brought users to the site in the first place. This might be a search engine, an advertisement they clicked on, or an email marketing campaign.