In May Google announced the support for embedding AdSense advertising in Google Maps embedded in publisher sites.
The advertising that appears is sensitive to either the location of the center of the map and to the site on which the maps are embedded. You can see the advertising changing as you drag the map around the world. Try it in this embedded map of PHP user groups world wide.
The map location plug-in class of the Forms Generation and Validation class was enhanced to make it easier showing AdSense advertising in embedded Google Maps just by adding a few lines like these to the definition of the map input.
The Publisher parameter is the identifier of your AdSense account. The Channel parameter is a custom AdSense channel that you may create to keep track of the performance of this type of advertising. The MaxAdsOnMap parameter is an option to limit the space that will be used to show advertising.
You can view a live example in practice:
Here you can see the example source code:
While the revenue generated by this type of advertising on the maps is not extraordinary, if you are an AdSense publisher of sites that embed Google Maps on their pages, it may help improving your sites revenue.