Lurk. Not as bad in actuality as it sounds, read comments attached to posts getting a feel to how others are responding without contributing to the conversation. Soon, there is a compulsion to add our 2 cents. This is not without angst. The decision to move from lurking to commenting can be a leap of faith, not all that dissimilar to being the new kid in class.
Comment. Often there is an option to do so anonymously or with user name. If the post is accepted by the existing community, it's easy to be emboldened and continue. After commenting as anonymous for a while there comes a time to take the leap and sign in. This means - yes - create an account. Why? Mostly for the simplicity of knowing our signature is the same every time a comment is generated. More importantly, take ownership of what is posted.
Interact. Now, instead of just commenting to the blog author posts, readers talk amongst themselves. Conversation is generated. If the posted comment name is a hyperlink (blue and underlined!), click on it and chances are another blog of interest may appear. And so on and so on and so on.
But, and there is always a but, what if most of blogging is just habit? How so? Take vacation. For me, vacation means NO COMPUTER. I know, I know, it sounds barbaric. Every day at work is eight hours with the computer. Then email and such at home, more time on the computer (granted it is a smaller amount of time, but time nonetheless). So a week or two away from the blog they lose momentum and importance. Is it to be expected?
Maybe it's the first step over to the dark side.