Player created Billboards that can be placed anywhere. In a claim area or not (could also be next to an inn or trading post in the middle of nowhere).
Basically it's medieval craigslist.
They could be used for trading, placing bounties on players, or even player created "quests". Players will not play 24/7, you will often pass by a village where nobody is online. That means you cannot interact with it in any way until someone comes along.
A sum of money could be attached to a particular objective that could be repeated as many time as requested by the creator.

Let me explain:

You are a blacksmith, you need ingredients like leather straps to create an item but you don't know how to skin animals.
You go to the billboard, and put up an announcement such as: "Need 10 leather straps, will pay 10 silver coins."
Some time passes, and a hunter comes across your village, the first thing he does is check the billboard (think The Witcher). He sees your announcement, and decides he will go hunt for you. He brings back the leather to the billboard and deposit it in a small chest. He automatically receives the reward.

Same goes for trading. You need 100 metal bands, you are ready to trade it against linen or leather. You put your items in the chest near the billboard, and write your ad. If someone sees your ad and has the items required in his inventory, he will be able to automatically trade them with the billboard.

Bounty Hunting, you could put a simple note on the Billboard such as "X is a criminal who has murdered many in these lands. A reward awaits the one who will put an end to his killing spree. Contact Y for payment."
Two ways this could go, either you don't add any particular mechanic and all will be left to players (proof of death, payment).
Or you add some item that gets generated upon death, like a severed head for example. This way the player who put up the bounty could know for sure the other player is dead. The bounty hunter (or should we say assassin ?) could bring back the head to the billboard and get paid. Or, if the target is the RolePlay type he could surrender and follow the hunter back to the person who put up the bounty.
This system is often abused in other games (GTA V, EvE Online come to mind) but in Life is Feudal, with alignment and skill loss upon death I doubt many will kill their friends just for a quick reward or to "get rid of" the bounty.

You can still do everything through chat / direct trading, but it opens new possibilities of interaction. Put up an ad, log out to go to sleep, tomorrow when you log back in new things may have happened while you were gone! And you made it happen!

Let me know what you think.