My series is going to span hundreds of chapters, most likely. I originally was going to have it just marathon'd and send it as one Volume. In doing so, it would just be one continuous adventure from start to finish.
However, I learned that breaking it down into multiple books allows me to set up sort of "blocks" where I can focus on characters, plot, and material for one block at a time. In between blocks, I can take breaks, reform ideas for the next block, do maintenance on the finished block, and interact with my readers more directly in each block as we go. It also allows me to organize my Plot Arcs because I can reference the Volumes specifically as I go, and each Volume is a piece of the overall series that can be enjoyed in isolation.
While they all piggyback off one another, you can discuss them more easily by saying "this happened in Volume 2" and then go find it there, rather than having to dig through all of the chapters to find what you're looking for.
This option isn't perfect because, like doravg mentioned, readers may want everything in one place and may not want to have to jump from volume to volume. But, I like things organized. Plus, both SH (ScribbleHub) and RR (Royal Road) allow you to break up your books into volumes and create references between them.
- On RR, you have the Series Function which allows you to organize chapters by volumes, and readers can also display all chapters if they decide to as well.
- On SH, you have the "Related Series" function, which allows you to connect your books and define them. Whatever you set is then displayed on your series' front page.
If there was no referencing function like those two options available, I would've likely been more inclined to be creative with my Chapter Titles to distinguish when a new volume/arc starts. However, because of the options, it was an easy choice for me.
IC; if you want to be organized, break things down into separate books and use the functions the sites give you to apply the referencing points for your readers so they can easily find them. If you don't want to be organized, then you don't have to but I recommend adjusting your Chapter Titles.