Take a look at the attached screenshot and you'll see my mouse hovering over the icon which tells me what state I've attempted to target my ad to. While it says "Tennessee" I've got a buddy who can see it and he's in New York.
It seems real intuitive, but I'm thinking that I'm either doing something wrong of there's a bug, there's a workaround that I'm not familiar with.
How do you do this successfully?
I found an article that says you can approach it differently, but I don't have the "Public" option on my page (http://todmaffin.com/geobug