On the Purpose of The Blog

Having been introduced to blogging, my first thought was to question the purpose of blogging.

Is it to fulfill the need all people have to express themselves outwardly?

Or does it fulfill some greater need to communicate your thoughts to others?

Is it a result of some societal development in the early twenty-first century, or does it reflect human need which is not restricted by historical development?

The ultimate irony being, of course, that this is a blog in itself.