You can not compare the two items. Adwords ads delivered to a searcher will result in a 1 in 7 click through. organic rankings #1 spot results in a 6 in 7 click through. an advert on a page will result in probably 1 in 50 or less click through, as people have already found what they are looking for on content advertising.
Excellent stats James. Which of the two medium can put your keywords on Google in the next 1 hour? Organic or AdWords? this is the point I am trying to convey to Bagi.
If you have time sensitive products to shift, you do not have time to wait to get to number 1 for the appropriate keywords with organic results, you buy AdWords righ away.