If you’re starting a webcomic for the first time and don’t have much of a name or reputation, I think most people would reasonably assume that they weren’t going to attract tons and tons of traffic as soon as the comic launches. You can get a leg up if you’re friends with some other comic creators, and they can help promote your new comic, but without some outside marketing assistance, it will take some time for you to build an audience. Depending on your style and talent (and more than a little luck) you’ll slowly see your site traffic increase and perhaps get more and more responsive and devoted fans.
But at some point, that traffic and interest will plateau. The venues you used to develop your following—whether that’s advertising, social media, a nice bit of PR from another site, etc.—will have exhausted their “supply” of potential readers, and further mentions will have less impact. Basically, everyone who might be interested in your work and see those spots where you’re highlighted will have already checked your comic out.
A webcomiker will see this in their site analytics. Their site visits and page views will rise and rise, until they don’t and they just level off. That’s when things have peaked.
The question that a creator needs to ask themselves, then, is: is that enough? Is whatever that peak happens to be enough for what they’re trying to accomplish. Whether that’s a certain number of followers, or a review from a prominent critic, or enough income to quit a day job, or whatever. If it is, great! If not, then the creator will need to decide whether they’re getting enough out of the comic to continue as is, or if they need to do something different.
And maybe that’s not a decision they want or need to make as soon as they realize they hit that plateau. Maybe they’re perfectly happy with things at first, but become disappointed or disillusioned after an extended period with no appreciable change. It’s perfectly alright and understandable to want to continue to move forward. No artist wants to remain static indefinitely.
Then the discussion needs to center around whether the comic needs some minor retooling, or if it should be substantially overhauled. Or, for that matter, scrapped entirely in favor of something completely new.
And again, this goes back to where the creator feels is the best way to move forward. Have they said everything they wanted to say with their strip, or are there more stories to tell? Is the art easy to do, or has it become tedious? Does the author still care about the characters at all, or are they just going through the motions out of habit?
There’s no right or wrong answers to any of these questions, but they’re ones that webcomikers will continue to find themselves asking periodically as they reach their personal plateaus. Which is kind of webcomics is all about—doing a personal work to help move a creator from one plateau to the next.