The best thing about blogs is that it gives your students an authentic audience for their work and reflections. Rather than doing a piece of writing and only having the teacher read it, posting it on a blog allows people all over the world to read it and comment on it – and they do! Clustr Maps and other statistics sites show you where people are reading your blog from and how many people have visited your site. What better reason for kids to make sure their work is correct and understandable – they can see that (possibly) hundreds of people have seen it.
A great thing about having an authentic audience is that it creates authentic conversations. A blog is definitely not supposed to be a one-way authority on anything. The idea of the comment functions on blogs is to continue the conversation above and beyond what a writer has written in a post. Comments add to posts and allow for many people to voice their opinions about what you have written. It’s a great way for students to post work and then get feedback on that work – no matter what language it is in, there will be an audience. The potential for interaction on a blogsite is incredible.
Here’s a great video made by Frieda Foxworth which gives the top ten reasons to blog with your students.
Rachel Boyd from New Zealand has also put together a video on why we should let our students blog. It’s worth checking out:
Those of you who already blog, reasons have you got for why you blog with students? Leave a comment to show how the conversation can grow! Thanks 
I totally agree with your reasons for blogging. We’ve had our year 6 students actually state themselves that they really tried with their writing etc when they blogged. They could see the value in well written posts because of the ‘audience factor’. The enthusiasm to write and converse with others was never ending! We tried to guide the students into reflective practices and voicing opinions through blogging, but found that there were also many other educational uses for them. We’re hooked!!