I think the best example of reader burn is if someone uploads ten or more individual episodes all at once. This is especially if they're just starting out on Tapastic. A full chapter or so every once in a while works because it can warm up readers and subscribers for what's to come gradually. However, twenty full-chapter episodes or fifty one-page episodes in one day can kill potential interest in the comic before it could properly emerge.
I also believe it can be bad for a series to do the exact opposite, when a creator uploads a twenty page update for the first episode, (a decent amount) but then slowly uploads just one page at a time at that point onward. This can work if done properly, but depending on how it's done, it can be very harmful for a series. Uploading one page every so often can either make readers crave for the next episode or groan that they have to wait all over again for the next. Playfully dangling a carrot in front of rabbits can only for last so long. At some point, you have to give it over to them or else some will lose interest.
If a creator is serious about uploading one page at a time, (either to create a buffer or for scheduling preferences) but what they upload in the meantime is not doing much for the plot, this can detract the reader's interest almost as much as reader burn, and it can also be much more deadly for the series because it can cause a loss in dedicated fans.
A big reason why is that when a series in the middle of the rising action in a story arc, it should eventually lead to some kind of conflict, or develop some characters, and eventually approach the climax itself. But to have the story keep trekking forever up the slope of suspense without an idea where it's going can ruin the pacing of a series, especially since the readers are only getting small snippets at a time. Even if the first part was exciting or if you have everything planned out, not delivering on the rising action for too long can make it seem like the series isn't going anywhere.
Of course, all of this ultimately depends on how you grab the reader's attention and how you deliver your story to the readers. To me, if there's nothing going on for a long while in your story (meaning it's only pointless filler... although intentional filler after a nerve-wracking story arc works just fine), I'd rather wait a while for a more satisfying update.
Some examples I know where the one-page-an-update actually work are harrodeleted's Demon's Mirror, Yufei's Outer Door, and @Strontium 's Heroes of Thantopolis. Because every update for each of these series, even if it's just one page, deliver something for the reader to dwell on, readers then have the desire to anticipate the next.
Here's a more in-depth analysis on each series:
Demon's Mirror works because it has captivating visuals and suspense, never holding you barred for too long to give you some conflict and delivering humor if there's nothing to conclude just yet.
The Outer Door works well because of it's overall tone, visual style and brooding themes overshadow the fact that we're still waiting for the next episode.
Finally, Heroes of Thantopolis works because the story is split up into proper lengths, each with a definite idea of where it's going and leaving you with exactly enough to keep you wanting more.
In short, there's a balance of how much you should upload at a time. Don't upload too much all at once, for it can cause reader burn. But don't leave your readers hanging in suspense for too long, or else they won't stay around long enough to see what it was all leading up to.