Can the Advertising boards be used when for something other than items? For example, art, writing, etc. I made a post on the Art Market, but wanted to show it where more people could see, and Forum Groups aren't open for the general public.

If you're advertising for writing, that's the Art Market. If you're offering these services for Subeta, that's still the Art Market. Forum groups help in that you have people join that specific group then you can ping that every time you make a post an get the word out to a specific set of people first.

If that makes any sense. I'm tired. XD;

Got it, thanks!