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.

Dear Customer,

In our next version 3.2.0, we will create drop-down boxes dynamically for each level which will be handy and hope you will like it. This version will be released next week-end.

Thanks.

I agree a City field would be good.

If the field isn't pre-populated with city names then let the member type in their city.

Thanks for your suggestion and sure we will pass this to our product management team.

Thanks.