Do you tend to read regularly updated sites via RSS, or do you point your browser at them?
I really don't like RSS as a medium for digesting site updates. I was using Google Reader for a while, but I didn't like the fact that I had to actively mark things as read. I much more prefer a passive medium such as Twitter or Facebook in which I can just scan my incoming feed for links that interest me and ignore the rest. So basically, if a site doesn't have a Twitter or Facebook account that it publishes updates too, I generally won't bother checking back.