With Adsense it seems to be about Location. I would really like to know what CPC publishers are getting in these countries lately: USA Australia Canada Singapore Sweden Switzerland Germany UK UAE Greece Any other countries that sometimes or always pay a nice CPC?
It actually depends on the advertiser and the niche too, you can found that sometime you get $3 per click from USA but sometime is might be only $0.30 per click. However, generally i can see click from USA, Canada and Australia is the best.
The richer a country, the more business there is (remove petrol monarchies) and the higher the CPC in adsense. So no wonder US, UK are number one It's good in a way because it promotes the english language, many people are improving their english only to work online
English speaking countries who are full of consumer, and whose majority of the population have access to the internet will be your highest CPC locations. In other words, USA and UK.