A third party application I have used for several years now, is "Geotag photos". They have a free desktop version and a 3.99 USD iPhone/iPad and Android app.
The main advantage of geotagging your images is the fact that finding specific ones becomes much easier. Even if the image is not (or limited) key worded, I can do a quick search by using the Lightroom Map function or by searching for all images shot in a certain city/area. I also sometimes get the question of clients or fellow photographers where the image was shot exactly.
Whenever, I don't want to share the geotag info, I just make sure that I tick the "Remove location info" box in the Lightroom export box.
Hope this clears up some of the geotag questions you might have as a photographer!