While most shops are owned and controlled by non-player characters,
there are a few shops in The Two Towers which a player can take
ownership of. There are also shops which a player can aid by
helping stock the shop's inventory.
Some guilds also operate publicly accessible shops. In these
guild shops, the members of the guild can put items up for sale
for anyone to buy with the profits going into the guild's vaults.
Some guilds will even stock their shops with items on-request,
or craft custom items according to the buyer's specifications.
For the exact details of these player owned shop features you
will have to log in and ask to learn which shops are in business.