Ok, here there are two different types of Job - Player Requests and Clan Approved.

Player Requests are made by Player's Characters that do not belong to a Clan. The rewards to these Tasks are put up by the Player's Character or the Player themselves. This means that a Player can put up unwanted Promo stuff as rewards!

Never wanted those 10 random berries? Want a Fire stone?
Then put up the Task asking for a Fire Stone offering those Berries as a reward.
Mods will also put up LV rewards too! So, even if you think the item reward isn't too good, the Levels you can gain from doing the task could just about make up for it ^^

Now, here is where the fun bit comes in. If your character belongs to a Clan, the task immediately becomes a Clan Approved Task! This means that, along with what ever item/money reward you offer, your Clan will also offer some form of reward too!
On top of this, there is also the Mod Level rewards, however these will not be as good as NPC requests or Player Requests of the same standard, due to the Clan pitching in. Players can also opt out of being Clan-Approved when placing their tasks by simply saying so in their Topic.

Also, if you can, post your requests as an in-character post. Just makes things a little more fun xD