When a location is added into your SLP data set, you will see a message “Store Locator Plus wants you to know:”  and the output of the Latitude and Longitude where Google thinks the location is.

For Example, I added Sydney Opera House and no street address, just name, the city and the country Australia:

“Google thinks Sydney Australia is at lat: -33.8674869 long 151.2069902”

Address location response when adding a location.
Address location response when adding a location.

You can right click on that lat/long and open in a new window, the Google Map with the location will be displayed. It is showing the Sydney opera house blocks away from the harbor, but it is Sydney. When I add more information and details i.e. “Bennelong Point” the lat/long is now at: -33.857123 long 151.2149798.

Still not exactly where it says it is if I go to the Public Search in Google Maps but close enough. Google uses a “proprietary algorithm” for performing a search in their maps that they do not  share. There are some locations that Google totally misses the geocode boat (for instance locales in Costa Rica).

This Wikipedia article explains why there are differences and how Google interacts with geocodes differently depending on the venue and location.

Store Locator Plus uses the Map Domain setting to help guide Google to producing the proper latitude and longitude for addresses both when geocoding new locations as well as when trying to figure out where a user is when they enter their address on the map page.