One of the “maxims” of doing webcomics is that, whatever your update schedule is, stick to it. It’s certainly possible to post updates randomly as they happen to get done, but that’s generally thought of as a bad move. Readers, like most people, are creatures of habit, and prefer the regularity of knowing that a favorite webcomic of theirs will update according to a set rhythm.
One of the other notions that often gets touted is that more frequent updates are better. As a creator, you want to establish that rhythm with your readers and it’s easier to do that if you can reinforce that behavior more often. After all, it’s much easier to remember that a comic updates every day than to remember that it only updates on Tuesdays and Thursdays, and crap, how did it get to be Wednesday already?
It should come as no surprise that a greater frequency is more difficult the more complex the story is. A gag-a-day strip is more viable on a daily schedule because the jokes don’t have to serve any broader storytelling beyond the three or four panels needed for a single joke. A longer narrative, such as one would find in a graphic novel, is harder because there’s more complexity and more moving parts to be juggled.
That complexity is seen by the readers. They will make a pretty quick judgement about how easy the comic is to follow between the complexity of the story and how much time elapses between installments. A single page every other week for a convoluted plot is going to turn a lot of potential readers off as too difficult to follow, whereas a simple gag every doesn’t require as much ongoing attention and focus. I was reading a webcomic a little while back where a single battle took several months to complete, and by the time it was finished, I couldn’t remember why the fight started in the first place.
There is an option for longer narratives that I’m surprised not to see in use more often. That is: less frequent updates, but said updates are larger in scope. Something like a weekly update schedule but each update consists of five or six pages. While that particular set-up still basically amounts to a page every day, it’s an easier read from the audience’s perspective since there’s enough content to see all the story components in action.
It’s certainly possible for a reader to simply save several updates and read them in batches, but why not make it easier on them by creating handy batches for them? The storytelling shouldn’t be appreciably different from a creator’s point of view, so why not make it a more enjoyable experience for readers?
As with any ideas tied to webcomics, that’s by no means a rigid suggestion. A webcomic’s updates and update schedule should be tailored to the story, the audience, etc. But sticking to a one-strip-per-installment model isn’t necessarily the best approach just because newspapers have used that for generations.