Understanding the Google “show map of” feature

Question

I noticed that the "show map of" link has recently popped up in the Google listings of some of my projects.

I searched on the net to understand the mechanics behind this feature, but I couldn't find any clear explanation.

So far, just two explanations came to my mind, please correct me if I'm wrong:

1. Google uses the addresses I set up in the Google Maps modules and concatenates them with the rest of the data of the page content.
2. Google extracts the addresses (some project have addresses in the page content), from the content of the pages and associates them with the rest of the data.

I would like to know how Google extract the address information from my pages to eventually "control" the use of my data. Also, I'd like to switch to an alternative of Google Map like OSM, and I want know if that will impact the "Show map of" feature.

Answer 1

Here's a 2009-vintage blog post, How to Get “Show Map of” Tag to Appear in Google Results by Michael David in Tasty Placement, which claims to have the answer. The method:

1. Generate a Geo Sitemap, a small KML file which names a destination (like a business), and describes the location of that destination with a place name and a latitude/longitude.

2. Register this Geo Sitemap in a verified Google Webmaster account.

This Google Webmaster Tools page, Creating Geo Sitemaps says that,d as of March 2012, Google no longer supports the Geo extension to the sitemap protocol. Instead, they point the reader to Google Webmaster tools page, Creating Sitemaps, but that doesn't talk about how to describe place names and latitude/longitude. But in this Google+ thread, Susuan Moskwa of Google says, "We still support KML files. We previously supported an extension to the Sitemaps protocol where you could include tags in your XML Sitemaps that contained geo-specific information in addition to the URL of your KML file. We no longer support those geo-specific XML tags in Sitemaps, but you can still submit the URLs of your KML files in a standard Sitemap format."