Games that manage this, such as EVE Online and A Tale in the Desert, manage to provide an environment in which players can affect the world they play in due to the fact that they share a single world. Portnow suggests that MMOs won't be able to provide meaningful stores in games that don't provide this due to not being able to change the world because different servers may have made different choices. Portnow goes on to explain in detail what the problems are with creating a single shard world and proposes some solutions to the design to support the large number of people involved. This includes the resources supporting crafting, letting the players build their own settlements and making the PvE content to make it interesting.

You can read the full article over at Game Set Watch.