Communicating with your followers may be important to your business. Newsletters provide a means to accomplish that task. You may offer different newsletters for different purposes, and followers may register (name and email address) to the newsletters of their choice. You may also create your own private lists based on some other email address collection method.
Newsletter templates provide convenient areas to insert your content, and emailing through your own site domain provides a free facility for communication as often as you desire. Statistics indicate what percentage of your list opened their newsletter.
Registration can be required for a list, or the list may be subscribed publicly. Registration may also require confirmation before the address is enabled, and notification emails can be sent to you for each new subscriber or unsubscriber. Initial sign-up newsletter responses can be triggered, if desired.
A newsletter may be sent to multiple lists, and an archive of past newsletters can be made available on your site as long as you want to show them.
These are but a few of the many options in configuring newsletters for your site.