George Bates shared a screen shot with me on Twitter of a new location extension named “affiliate location extensions” in AdWords. It shows the “relationship type”, the country and the available chains you can pick from.

I am not 100% clear on how this works, but it seems like you can define if you are an affiliate and then select the chains Google has available.

Here is a screen shot:

You can see chains such as 7-Eleven, AT&T, Babies R Us, AutoZone and many more popular retail chains.

Again, I am not sure how this works exactly but I suspect we will learn more over time.

Forum discussion at Twitter.

Update: George added more details about this over here.

Update 2: Google announced it 30+ hours later on Google+.