It depends where the ads are running. Ads you see on big content sites are almost always on a CPM model. Fixed price ads (like you see on TechCrunch or TheDec

It depends where the ads are running. Ads you see on big content sites are almost always on a CPM model. Fixed price ads (like you see on TechCrunch or TheDeck) are generally based on a CPM rate. Pay per click ads aren't generally worth enough money to sustain sites that produce content. Aggregators, search engines, social networks, etc, have a much, much lower cost per pageview, and can do pretty well. On Ars, we'd need to average about 50,000 pageviews per normal post to pay the writer for it with something like Google AdSense. And that's assuming that the campaigns AdSense picks are pretty good. There are whitepaper links and stuff you can get much better CPC rates for, but those generally only work if you're sneaky about them and embed them in content, or make them look like site resources.