Have you ever been to a night club and seen those long lines with the velet ropes and a bouncer letting people in one by one? Just because there is a long line doesn't mean the club is full. It doesn't even mean the club is any good. The night club owner is creating the *impression* of demand by keeping people waiting outside. Others drive by and wonder what they are missing and soon they get in line themselves.
You can do the same thing yourself by "seeding" the comments on your blog post. When you post an article, save a little of what you have to say about the issue and post it as the first comment. Once people see that a conversation has started, they are more likely to join in then they are to start one themselves in an empty room.