As Russ pointed out, it was likely done for external applications and is an attribute of an address, which is not module or document specific. 

Having geocoded information can be very valuable depending upon the application.  I worked at a company that contained "mapping" information in the database that housed every address in the state of California.  Prior to geocoding, it was mapped by Thomas Brothers' map page (I think they still actually print a couple of them).  Moving to geocoding allowed us to then implement a "centroid" search defined by the user's desired distance to find properties within x miles of a target address.  The real estate appraiser application then gave better answers and allowed us to no longer maintain Thomas Brothers map pages relationships.  This is assumed today, but back in the 80's/90's not so much.

In 500, I could picture something like using the information (if it was populated) to help determine delivery routes or vendor distances.  But as far as I know, there is no 500 native usage of the data.  I was not originally involved with its design or implementation so I do not have the history knowledge of the whys or whens.

That's exactly what I did for a client that had a requirement to schedule their trucks of cement from various facilities to client sites using the Google APIs.

That's exactly what I did for a client that had a requirement to schedule their trucks of cement from various facilities to client sites using the Google APIs.