E-commerce Analytics (or E-commerce Tracking) is a tracking method that analyzes data about purchases of products and services.
In addition to the typical analytics data (like Page Views, time on the page etc.), information about products viewed, transactions and purchase behaviors is monitored.
The method is used to get to know the preferences, habits and other information regarding the user. This provides the opportunity to personalize the content as well as marketing campaigns.
More about the E-Commerce Analytics on Piwik PRO Blog: