If I create a site targeting the keyword of, I dunno, "Best baby diapers"
now let's say there's 20 competing Ads for that keyword on Adwords, and the average CPC is $2-$3 a click (so let's say these Advertisers are spending $10-$20,000 a month to advertise for a high traffic keyword)
Now if I spend a year developing the site, getting it ranked in the Top 3 of Google for "best baby diapers" and manage to get it a PR of 4 - 5...
Would it be possible to sell that site later for enough of a ROI to justify a living of it? Assuming you do this over and over for multiple sites?
Basically, is there money to be made by building websites to target keywords with a high ad-base also targeting them?