Google has just opened up a substantial swathe of inventory for AdSense, most of which will be filled with local advertising. AdSense has just announced the Maps Ad Unit for mashup developers using the Google Maps API.

The default implementation serves up 2 AdSense text ad units in a box somewhere along the perimeter of the map; tweaking a parameter in the code can serve up only 1 ad unit instead (for smaller maps). You can see an example of the 2-unit at ZipMaps, and a 1-unit at Acme Mapper. In the example to the right, we’ve pinpointed YieldBuild’s ZIP code; the ad served up is to Roy’s, a Hawaiian restaurant not even a block away.

Google Maps mashups are popular—1688 using the API at last count—and are probably a great way to build local advertiser inventory when mobile map advertising, where the real money is, becomes viable.

YieldBuild will be exhibiting at SES San Jose this coming August 10-14 (booth #516).

If you’re attending and are looking to save some money, feel free to use the following discount/promo/priority code when you register: 20YIHU

You’ll get a 20% discount on any conference pass!

I’ve attended SES for several years now, and found it to be a great show for its sessions, exhibitors and networking opps. It really is the definitive SEO conference series.