I noticed that certain posts are gaining an unusual amount of traction from the the spamming crowd. So I am trying an experiment. On "Dangerous Student Loans" and "Running out of money is no fun" I am showing existing, but closing further comment. I actually get noticeable traffic to these posts (at least the first one), but I suspect at least a portion of it is from the guerrilla marketing people.
Real people do look at older posts. I still get a fair amount of traffic from the Texas school kids looking for information on Karankawa Indians- particularly those trying to figure out what there homes looked like - hint: they likely were a group of Caribe Indians who settled on the coast - but term paper folk never leave comments.