NPC XP for everyday tasks?

Is there any mention anywhere on how to award
XP for performing 'daily duties'.

I'm not just looking for an explanation to how
commoners and experts gain levels, but also
trying to avoid the problem the local (non-
adventuring) cleric gets when he hits the
bottom possible xp of his level and can no longer
make and sell potions eg. Without some non-
adventuring way to make XP for these people
evereone would at one point end up with no xp
to spare, and even the most pitifull magic
would no longer be available anywhere.

//Finn

Its best not to think too hard about D&D.

Seriously though, those people get their experience by doing what they do. PCs get experience for being adventurers. Presumably, blacksmiths get xp for overcoming challenges inherant in being a blacksmith, farmers get xp for being farmers, and homebound clerics get xp for tending to their faithful. The exact system hasn't been worked out because it isn't needed.

The best way to do it IMO is just to make it up. You need a high level blacksmith, make one up and don't worry about where his exp came from. Want that cleric to turn out healing potions every day. Just do it and don't sweat the details. Now if the PCs want exp for daily work thats a different story