That’s a tough question. I feel that I have one, but I have hard times to properly put words on it (even in my native language). Maybe I’m just used to have this kind of parent category, like phpBB, eh…
Let say I have a gaming forum.
I have these categories:
news
video games
– pc
– console
hardware
jobs
– searching
– providing
Don’t you feel that searching and providing are in their right place, under the jobs category?
My main categories are unrelated between each others, they have their own purpose:
news, video games, hardware, jobs.
But wouldn’t it be weird if searching and providing were both on the same level than news, video games, and hardware?
news
video games
– pc
– console
hardware
searching for job
providing job
Yes, but in the all categories menu, the displayed number of posts doesn’t take account of the subcategories (which is a weird choice in my opinion, are there plans to change this in the future?), so the users would see: classified ads x 0… Which is not right.
And they’d have to click on the (apparently empty) category in order to see that there are indeed topics:
Another issue is that when a user goes to the classified ads category which lists by default all the topics from the subcategories (buy and sell), the “create a topic” button will be disabled, which is also not right.
How does the user know that he has to actually go inside a subcategory in order to create his topic?
So actually I’ve put my buy and sell categories on the top level, I think I have no alternative.