Notice also that every entry on this page has a link at the end that allows users to leave comments. Making the site interactive like this is s a great way to keep people coming back.
Comments are optional, and on your own site you will have the ability to turn the comments on or off at will. You can even install multiple Blog modules and have comments enabled for one and disabled for the other. For example, you might set up a News page that does not allow comments, and a separate Journal page that does allow comments.