Also consider that blogs get different comment rates depending on what they are about. My wife's blog gets about 10+ comments per post with only 100-300 unique

Also consider that blogs get different comment rates depending on what they are about. My wife's blog gets about 10+ comments per post with only 100-300 uniques per day. Sometimes a traffic spike will bring in a bunch of extra hits, but the amount of comments left after the spike depends on who was coming in. If it was a bunch of web developers or something: zero comments, even over thousands of hits. A minor conclusion I draw from this is that blog comments come from community people, visitors and fans who keep coming back. The "jadedness" of the community is a far bigger factor though. Some people are on a quest to consume, and not necessarily to participate.