Kontera is tricky with value of the clicks. I used it for month or two, but altough number of clicks was bigger and bigger every day, my earnings were going up and down (!) - strange, but true. In addition, Kontera pays so little, that is not worth using it at all (like one or 2 cents per click, or something like that).
After more then 2 years of writting here, I can warmly recommend you to use Google Adsense only.