I assume that you refer to Adsense CPC as that's the most prevalent advertising available on the market today?.
If you, like million others used Google's Keyword Tool to determine the CPC of any keyword, remember, that tool is there for "advertisers" to determine the cost of placing their keyword in the # 1 spot.
As a publisher, for your $11 CPC keyword, if you were to receive a click, you'd get about 68% of that, so approx. $7.48 for that click! But remember, the CPC would change depending on the type of traffic you're getting (organic, links) and if Google determines that the advertisers are not getting a good ROI, then they can within their TOS change the CPC publishers are able to be paid.