What is the market area?
- An area dedicated for shops
- It'll be possible to do auction in that area using a plugin
- A stadium for events, and stalls outside the stadium (Like in Slateport city in pokemon emerald)
- PokeMall - Like in Lilycove city from pokemon emerald.
- A special chat, especially for the city. (To reduce spam in global chat)
I think the Market area would be a very nice place, and it can also help reducing spam because it'll have a separate chat for trades.