Trading: Sell/Buy Orders Social addon

[Solieus]

Is it possible to make an addon that interacts with other characters on a realm-specific basis?

People keep asking for buy/sell orders to be added to the AH UI in developer interviews. Can it be done with an addon first?

It can work like in-game message board pretty much. Someone makes a post asking for so much for an item, and then someone else can CoD them the item in the mail

There can even be a specific system that can track people's records, so you know which sellers are reliable / sell a lot or which buyers are reliable / buy a lot.

Is this possible?