Empowering over 30 million websites (estimation) over the world, GA is one of the most powerful and free tools for webmasters.
GA provides you in-depth analysis of user behavior, interests, demographic information and so much more about your visitors.
You can use this information to make your website more user-friendly, improve the interface, increase conversions and monetize your website according to your preferences.
GA use sophisticated machine learning algorithms on the backend which can help every website including e-commerce, agency, store or else. Further, you can also combine Google Analytics with the mobile and web-applications.