comparison of the advertising rates on the three most popular blogs on earth.

TechCrunch.com - This Mecca of Web 2.0 generation generates over 2 million page views per month. Advertisers can rent prominent 125x125 banner space on Techcrunch for a fee of $10,000 per month which translates to a $5 CPM.

Lifehacker.com - The average CPM for image banners is $8 while a 7-day text link on Lifehacker is available for $100.

Lifehacker receives around 200,000 views per day so a month long banner campaign on Lifehacker could cost you $48k @ $8CPM.

BoingBoing.net - This directory of wonderful things handles close to half a million hits per day.
A 125x125 text ad on BoingBoing costs $350 for a week while rectangular banner ads are available at $20 CPM.