Had to break this into two posts because it's a bit lengthy, but I promise not to go off track. Thanks in advance for reading.

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Even if it worked as intended, I think sharing MB access across servers is not good for the game.

I used to play WoW from Vanilla through WOD (and a little in Legion/BFA but I checked out by then.) Servers had a community and identity. You knew people, even if you didn't know them as a friend, you routinely saw the same faces. Sometimes you knew people who ran certain dungeons a lot, or people who crafted and sold things. Some were nice, some were jerkbutts, and some were so pants-on-head everyone just had fun laughing at them. People had a reputation. This server had roleplayers, that server had PVPers, this other server had hardcore raid guilds, etc.

Why is this relevant in discussion about the market? Because the market is an extension of the players. I remember a guild on my server whose mission was to sell as many Righteous Orbs as possible, and so they farmed, and flooded. Their actions had impact on the server economy. It was interesting. There was another very popular tailor that barked "Pixie Packs" all day every day, bags with her name. But everyone knew if they wanted bags they could buy them from her. It added flavor and life, because in a smaller market, what you personally do matters and is more impactful.

WoW eventually added cross realm zones. Players from different realms automatically shuffled up into different instances of different combined people. That person you always used to see dancing on the mailbox wasn't there anymore, because they were in a different instance, or you were. Some people were happy, because you could now group and play with your friends on other servers. It's like being excited that you can hang out with your distant friend from Chicago every day now ... but only because the entire population has moved from there into your small town. Nobody knows anyone else anymore, every face is a new face. But one thing they didn't do was merge server auction houses. And, strangely enough, that (and some high profile guild name recognition) are pretty much the last places that server / community identity remain in WoW.

FFXIV is attempting to take an opposite-ish approach. Instances of zones are not forced together with players on other servers (thank you SE, this is the right way to do it) but we still have the pleasure of being able to hop over and play with our friends (on the same data center, at least.) They even prevent you from gathering timed nodes elsewhere. Good foresight. However, combining market boards into one huge pile removes that aspect of identity and, as the initial poster talks about, combining market boards removes an element of market-related gameplay from a large amount of hands and puts it in a small amount of hands.

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