My recent story "Moving On" has 1904 views right now—enough for me, but not many for something that was in the feature box and on Equestria Daily.  It's seems to be a story that means a lot to a small number of people.  Per view, it has a lot of thumbs-up, and it has 471 favorites—almost twice as many as "Fluttershy's Night Out" with 7812 views, and half as many as "Mortality Report" with 12,108 views.  It also has a lot of comments (118).

I glanced over my list of stories and noticed something funny.  The more views a story had, the fewer comments per view it had.  So of course I graphed it.

(Not that I'm a nerd.  I just know you guys are.)

The horizontal is views.  The vertical is comments per view.  I thought people coming from Equestria Daily might leave fewer comments because they don't have fimfiction accounts, so I marked the EqD stories in red.  The story with the least comments per view, Fluttershy's Night Out, was on EqD but not in the featured box, and got mostly views from EqD, while DDKRN above it at <8192, 0.03> got most of its view from fimfiction.  So there is something to that notion.  But it still looks like less-popular stories get more comments per view.

The obvious explanation is that the people who read the less-popular stories read fimfiction fanatically, or are Bad Horse compleatists, and might be more likely to leave a comment.  Or, seeing pages of previous comments makes people less likely to leave their own comments.  I know that's true for me.

A more-interesting explanation is that popular stories don't speak especially strongly to anyone, while less-popular stories might.  I don't know if I believe that.  Star Wars and Lord of the Rings speak powerfully to a lot of people.

Either way, this suggests that as your audience grows, they become less-involved on average.