Rules (however arbitrary) tend to make things more interesting. We recently discussed why Ninja Post limits threads to 500 posts. In short, the goal with this design decision is to limit “content sprawl” and keep threads in a format that is easy for users (both old and new) to digest.
In addition to limiting the size of a thread, we have found that automatically archiving older content ensures that things stay fresh and interesting. This approach fits with our broader goal to keep Ninja Post fast, easy to use, and fun for users. While resurrecting an old thread can makes sense in some instances, bumping antiquated threads is generally frowned upon by users within a community. It is usually more effective to create a new thread.
The concept of setting limits to enhance usability is a popular technique used in countless scenarios. Would basketball or football or soccer be as intriguing if their respective fields had no boundaries? Most certainly not. Although Ninja Post permits significantly more leeway than Twitter’s 140-character limit or the three lines and 17 syllables of a haiku, we believe that providing some structure and some limitations ultimately has a positive impact on usability because it ensures content stays relevant and fresh.