I'm only currently blocking Iran, Hong Kong and china. Is it worth just blocking everybody bar the Americas, Europe and Australia?
Why block Jamaica if you won't receive much traffic for them? The 2 people who visit your site won't smartprice your account :D
Why block Congo if you won't receive much traffic for them? The only person who has internet there and will visit your site won't let Google smartprice your account :)
Well here are my adsense stats so far ...
These are stats from running two proxies :)