I have read in a lot of places that CPC depends on the value of "keywords". However I don't understand what this means. I will set forward some scenarios.

1. Suppose I run a blog about knitting and this is a low paying niche. However I suddenly write five frontpage blog posts about forex trading and insurance. When people click on the frontpage ads, would I be getting paid for the low CPC knitting content or for the high paying forex content?

2. Suppose somebody finds my webpage by searching for knitting. However the actual content of the landing page is filled with high paying keywords. Is the CPC for this page determined by the low paying search or the high paying content?