One of my favorite games is FF tactics or FF 6 in some countries. It was the first game that I can think of or know of that introduced this type of job feature. This job type of feature is still available in some of the newer FF's and other games (Borderlands,ect.)
What it is:
You would go to a Bar/tavern/billboard and talk to the Bar keep or look at a poster or sign on the wall and it would give you an assignment you could select or register for. You would have to find a missing person/item or Kill a Monster that has been terrorizing the town.
I was thinking this could be something that would be doable to add to Classic. I would say for the most part the rewards should be just Gralats,but you could throw in any items as well. You could also use this to introduce the treasure maps. As in you talk to an npc they say they buried an item and they would like you to retrieve it and here's a map that leads to the location go dig it up.
Just as an example: You enter the Bar in Onnet nearest the Onnet general store and talk to the Bar keep. He tells you that a beast has been attacking people in Onnet forest and if you where to except the job and go kill it and come back with proof he would be happy to reward you.
So you go to Onnet forest and walk around until the Beast pops up at random and attacks you. After a brief fight you manage to slay it and you get a Beast fur spoil that you can give to the Bar keep as proof. So you return to the Bar in Onnet and hand over the beasts fur to the bar keep and he gives you like 2k gralats and gives you the option for a 2nd job if you would mind taking the beast fur to the shop keeper in nefrets river shop.
Once you turn the beast fur over to the shop keep she gives you an additional 100 gralats for your trouble and tells you if you return in 24 hours she will have a hat for you to purchase. Then you return in 24 hours she will offer to sell you the hat she made from the fur. Yes she has to sell it to you even tho you did all the work its still a shop and still a business and she has to make money but since you did help she will sell it to you at a discounted price if you buy now. You can buy the hat now at a one time discount for 500-1k off the normal price but once you leave the shop the offer expires and you would have to pay full price to buy the hat in the future.
You wouldn't have to do the 2nd part I just added it to make it into more of a quest. You could just do the first part up to killing the monster and returning with proof for a reward and it would end there.
These "contracts" or jobs wouldn't have to be added or updated all that often. They could be available weekly,biweekly,or monthly. My suggestion would be to have several jobs available like 3 and they get changed out once a month. It could be away to introduce new items,and be away to have small quests.