You can enlarge the graph by clicking on it.
Here's an interesting glimpse at Piperka, the web comic bookmarking site.
The vertical axis is number of Piperka subscribers for a comic. XCKD is first with 304.
Moving right in jumps of 50, we see the number of subscribers associated with each jump. They quickly fall into the twenties and then down to a huge number of comics in the single digits.
Piperka has just under 2,250 member comics.
The most interesting conclusion is that there are over 1,000 comics which could move up substantially with just a small boost in subscribers. I don't know how many readers opt to browse comics by popularity, but if you're at 1450 with three subscribers, and you triple that, you move to about 750. That might be worth the prestige value alone. Someone scoping your comic for possible ad placement might be turned off by a low Piperka base, even though it says little about your comic's true traffic and merit.
Of course, most of us don't put Piperka promotions on our site because we don't want to cannibalize our traffic. I'm looking into ways around this, and will report back if I learn anything.