It's a system for a feedback loop. If I have a blog for subject, I would still like to understand what it is my audience want to know more about such a subject

It's a system for a feedback loop. If I have a blog for subject, I would still like to understand what it is my audience want to know more about such a subject as to guide what I write in the future. What this is supplementing really is just email, in a more passive way.