I know a lot of us think of bad traffic (like Iran and Chinese) and how it effects our earnings/resources. While some companies don't mind this type of traffic, most don't like it. So most of us do the following:
1) Redirect it to another domain.
2) Leave it and take the small earnings, but risk getting smart-priced.
So I was thinking this:
Make your proxy with AdSense ads and all, but then set up a GeoIP redirection to redirect all bad traffic to a different directory, IE /iran/
So if an Iranian visitor goes to guardtunnel.com they will be redirected to guardtunnel.com/iran/
This new directory will basically be an exact copy of the old one, except you replace the ads with some company's like GlobalInteractive or CANEP or something like that, to preserve your AdSense. It's better to get 5 cents/1000 impressions compared to 1-2 1 cent clicks/1000 impressions.