Why Blogs in the Mathematics Classroom?

I've been thinking today about why a teacher would use blogs instead of a notebook for student writing. It's a good question. Blogs take longer (as opposed to a notebook) and are really just a different medium for having students record their thoughts--wouldn't it be easier for students to just open a notebook and complete that day's entry? I've come up with a few ideas:

1. Blogs are public. This fact leads to several advantages:

(1) This makes student writing available for viewing by parents, teachers, adminstrators, & other students.
(2) All of the above are able to make comments, thus opening up the possibility for a student/teacher dialogue, student/student dialogue, and on.
(3) Students are motivated by the fact that their writing is on the Internet.

2. Students & teachers have access to blogs from home, school, grandma's--anywhere that there is an Internet connection. As long as that connection exists, there are no more excuses for not completing writing assignments.

3. Blogs are paperless.