[EverythingEverywhere]

I think comments are not a good measure of traffic or readership.

I have about 300 RSS readers and another 300-500 visitors per day. MAYBE 1% will comment and they tend to be the same ones.

Commenters tend to be the top of the reader pyramid. They usually only comments after they've been reading a while. 99% your and every site are lurkers. I never comment on most sites I stumble, even if I like it. Usually I have nothing to say. At best I will hit the RSS button then move on.

The goal is to get exposed to as many people as possible, and hope that a small percentage will come back. Rinse and repeat. Once that regular traffic grows, you will get more commenters. The rate of increasing comments will grow much slower than almost any other metric.