If you're investigating something or looking for something you need an npc for during the next game then I suppose an IBGA would be cool. Those are what I've done in the past. If you're posting crafts for sale for players then the boards would be the place- I believe npc's read those too. ^_^
For instance I have two craftsman things I do but I never IBGA them. Since I receive money at logistics it's assumed that I've just been working odd jobs during the down time.
At least that's my understanding. Hope this helps somewhat.
-Crystal