I have been keeping written journals for over thirty years. Not consistently. But I often turn to the page to write out my thoughts. It helps me process them.
I see blogs in a similar way. Since they are immediately public, I try to write only what seems appropriate. I still turn to my private journal for complete freedom of expression.
Also, I see blogs are sort of verbal busking. What I mean by that is that I throw out my ideas (sometimes recordings or poems or what-not) into the big soup of the Internet. If people run across them, they are welcome to them. If they want to respond, I am glad to hear their responses.
This last part is one of the reasons I am using this format for my blog now.