Well, I've tried comparing their data with what google has on their keyword tool, almost the same. However, they don't account for the portion that you actually book from these values, so thats tricky!!!
However, they are very useful with their suggestions of the possible Ad buyers list on the left.
If you want to get more cash, and your website has lot of organic traffic, then approach they advertising prospects with a CPM pricing. Thats the best model for you and the advertiser. They will pay less than Adwords, and you will book more revenue than adsense
Just my 2 cents
Good Luck.

Great thread.. I would be looking for answers on this one Guys anyone experienced here? Or anyone know a free tool for analyzing cpc?

I think the tool is really good but the problem is its not working run time they generate report on monthly as the serp changes they know after 10 to 15 days.

There is a better tool for you: spyfu