Dàchéng encouraged me to blog on this:
I'd like to see more development of your very interesting ideas on hauling goods over trade routes. You touched on it when discussing travel here, and developed your ideas here, where I pointed out that the actual hauliers would get ganked by bandits, or bored by repetition, or both. You followed up on that here, pointing out that the repetitive nature of travelling trade-routes could be soothing rather than boring.
All the same, I think there's some fun missing, from the haulier's point of view. I understand that you may not want "action", but some other enjoyable or interesting activity has to take its place (I like your idea that just building tension can keep hauliers interested).
The point about trade is that it is more than just the process of trading. I wrote before, in one of the posts you linked, that it is impossible to make hauling goods short-term fun for most players. Hauling goods can be safe / dangerous and short-range / long-range. That's it.
There are a few interesting decisions involved, but the real reason I want trade is not because trading is so much fun. Let's face it: For most people trading isn't as much fun as fighting anything.
I already argued that it's not a good idea to make trading any more action-oriented. My point is that trading is fun for a few people and, optimally, safe short-range trade can be relaxing for some players, just like a daily quest. Not really exciting.
The real reason I want trade is because it is fun for all non-traders. They are the majority.
Imagine a huge fantasy world. One were geography matters. No teleports, two-digit amount of hours required to go from one end to the other. Gameplay-wise each big city and its environment acts like a traditional server. But you can leave this 'server' and can go to another city. (Clarification: It's a completely open world. But most of the environment is empty of players).
The short-range trade is mostly safe, but long-range trade is dangerous for PvE and PvP reasons. Now, imagine we put some magic-deflecting material into the game. It can be mined in just one mine. What happens is this: near the mine this material is rather common and rather cheap. But in lands far away it is very expensive.
Why is this good? Because it offers diversity! The magic-deflecting material changes the balance of the entire game. Warfare between player factions is completely different near that mine than far away from it. Now imagine lots of other items that are area-specific, like that ore from the mine.
The world becomes alive! You can explore the different areas as a player and learn about them. Sure, you can also learn about them on the internet, but to experience them you need to visit these areas. Just like in any good fantasy world, materials from far away are expensive and in combination with other materials from other far places powerful.
The world becomes an interesting place. You can learn about this place. There's even different balance depending on where you are in the world! We replace some finely-tuned gameplay fun (WoW) with an interesting place to explore and interesting interactions between players in an often un-fair, unbalanced world.
This design contradicts todays industry-standard of finely-tuned gameplay loops: the idea that you first make the first 10 seconds fun, then the next 5 minutes, etc. Instead, it enthralls the players with the promise of adventure and exploration that drives them forward!
If you ask me that is what has driven players forward ever since the first leveling game. That finely-tuned gameplay isn't unimportant, either. But we all know how boring finely-tuned daily quests are!
Abstractly speaking, we don't introduce one finely-tuned pattern into the world that players can explore, but many patterns that interact and thus create new patterns. This interaction of patterns happens via the players. Thus we trade one finely-tuned pattern for many, much more interesting, patterns. This is (passively) player-generated content.
A player-run economy with trade is invaluable for this game. Not because being a trader is so much fun, but because adventuring in a world with trade and traders is so much fun.