Blogs and language learning

Some questions have been surfacing recently (as part of a TESOL online workshop) about the use of blogs.  When deciding whether to use a blog or not, an educator typically must ask the following two questions (among others):

1. How can I use a blog to further my own teaching practice?

2. How can I use a blog to further the achievement of my students?

Understanding that there is some overlap in asking both questions, I will focus more on the former.  Notice how the video below presents a discourse among individuals interested in language learning:

The benefit of a blog is that individuals can create discourse through asynchronous communication on topics of interest.

What are your thoughts on using blogs, either as a means for promoting your own learning or as a means for promoting student achievement?