It is interesting for marketing purposes to see how often a newsletter has been opened, and which links have been clicked on. Below is an example of an overview of how often newsletters have been opened.
Usually a website uses a tracking system such as Google Analytics to measure visits to the website. The newsletter module automatically replaces the links in the text so that the usage from emails will also be registered. Not only the time when the newsletter was opened or from which country, but also on which link was clicked, and how often someone visited a page from the newsletter can be viewed. In this way, the marketing department has all the data in one place.
(google analtytics is not part of this manual)