What Adwords cost is not necessarily what you will earn with AdsenseYou're missing a critical ingredient here -- SMART PRICINGNo one knows how this actually works. But it can affect the pricing of the ads on your site. If the advertiser paid for $0.50/click - but your site is smartpriced - then the cost may be discounted lower (e.g. $0.25). So you may try to develop a site based on high paying keywords but if smartpricing gets to you, then you may not get as much per click as what you are expecting from your keywords.Here is Google's explanation of smart pricing
https://adwords.google.com/support/bin/answer.py?answer=9562&query=smart+pricing&topic=0&type=fGoogle's smart pricing feature automatically adjusts the cost of a keyword-targeted content click based on its effectiveness compared to a search click. So if our data shows that a click from a content page is less likely to turn into actionable business results -- such as online sales, registrations, phone calls, or newsletter signups -- we reduce the price you pay for that click.I find it fruitless to chase after the so called high paying keywords. There's only one simple test: what keywords are targeted towards people very likely to spend money? You have mortgage, credit cards, business opportunity, travel -- and those are typically the type of topic likely to make you earn higher from Adsense
