I work on a story based comic and am well aware of all the problems that come with gaining new readership. Firstly alot of people who are mad about story comics can also be very cynical and have pretty high standards. Since a story comic is long you have to make sure what you write is worth someones time, don't dilly dally about, make every page or strip matter. I've recently gotten into the habit of using an infinite canvas, meaning that there is no standard strip length, they're as long or short as they need to be. Working this way means that each strip is a "scene". Basically, no strip starts off mid-sentance or halfway through a conversation (except the last few). So I make sure each strip starts and ends properly, and I've had some strips end up really long just to make sure I ended a scene right.
The other thing I guess is, even though my comic is sorta serious, I have humour strips every so often, like the latest one, which are part of the story but in no way advance it. They're just there for a quick laugh.
I also have a gag strip comic which I ended a while back called Sub n' Scorps. I got more hits out of this comic than I could ever hope to get with Chooken, simply because it's a gag strip and people could get in and get out quickly, with no commitment.
Gag strips are like a one night stand, you can give them another go, and who knows, you may even end up spending all your time with them.
But Story comics are a commitment, you're in it for the long haul, and some people just don't like to commit...