It really depends on the author and their personal preferences, as well as on their buffer as they post. Generally, section-length varies between 7 and 15 pages (normal font like Times New Roman 12 or Comic Sans MS 11). There's no rule though. The only thing is that posting too little leaves no room for many comments, and posting too much can overwhelm readers. So the trick is to find some middle ground.
Oh, and did you know that once you've mentioned that you're writing a story, you'll get nagged and nagged and nagged and even more nagged until you post it?
