You are able to manage the complete content and structure of your site. It is easy to alter the look and feel of your site. No HTML is needed. These are generally your type of business, contact details, products, services and so on. Generally this is the first venture for a company into cyberspace.
Contributing editors can add pages or stories from the comfort of their own web browsers.
Each of your pages is a discussion group messsage. This is perfect way for a software company who has documentation which needs to be appended by their users - in effect the documentation becomes live. Of course, you can monitor and moderate these messages . Also, you can bulletin your members when something important crops up. It is one of the earliest versions of a website.