I looked at your 2 sample sites and I do understand so what I've done may not be for you but in case it is, I'll explain.
Mine is very simple but not ideal.
Using an unlimited number of sites with each site using deferrent theme, layout, apperance and plugins, etc. The caveat is they all use the same database causing ALL ads no matter from what site they were entered into to appear on all sites. This can be a drawback if there are sites offering specific but dis-simular items. I.E., a automobile site and an employment site for example but then I have to wonder why use the same databse then. It is a huge plus if sites are similar such as real estate or if, as intented, all sites are mixed item sites.
I've been moderately successful in "editing" out certian catagories/sub-catagories from appearing on certain sites but this is done on a site by site basis and by far not ideal.
As for location.
In admin, settings, locations, I do have United States as Country but I also have the following created under "Add new".
Site(s) focus is U.S.A so under countries, I enter a State name.
Under regions, I enter Counties.
Under Cities, I enter Cities. even sub-divisions. For large cities I have entered south side, west side, etc.
This gives each site/item entry the opportunity to chose specifically where the advertisement is to be placed as for location.
Likely none of this helps but if you can glean any ideas from it then great.
Tom
What do I know. My job is breaking things - NOT fixing them....
