The system has location, address information, zipcode and Long/Lat information in ads.
I run into the following 'problem';
Locations is not handy, as I need to keep track of all possible locations in the US. If you want to use Location information at a city-level, I would have to setup all cities of the US and users would have to choose from a long list of cities. This is not very handy.
Address information is nice, however, I do not want to disclose full address information of ads, users would not like that. However, If I want to show a map of the advert, I would need to disclose the full address information.
If I only use the zip-code, I cannot show a map with the location. (The map is oriented around the address information, not the zipcode information.
Long/Lat information is only created when the address is used. (If you want to show the map, you will have to show the address)
I suggest the following;
Add a field Country and City
This would provide sufficient information to show on a map, but not disclose all address information.
Naturally the address information can be given, but you can choose to not show that information to other users.