Once they have a Blog address, I paste into a google sheet I've set up in the "About" tab in classroom site. Every student can access this spreadsheet, not just me. (I did lock the sheet, so they don't accidentally delete anyone).
This part is where real communication occurs. They're not just writing for me; their whole class is the audience now. Now their posts get a comment from me and from their peers. To make sure everyone gets comments, I ask each student to comment on the person listed above and below them on the roster. The next blog post might get commented on by the names two spots above and below. Eventually, everyone has read and commented on each blog.
This method has worked really well for me. It's my way of helping my students develop their voice.