I wouldn’t say that Google Adsense revolutionized the web content business, but it has been “pennies from heaven” for content sites.
Just to get an idea of the scale of the money from the AdSense, here are the biggest earners (the numbers are mostly from 2005-6)
(i) PlentyOfFish.com: Adsense earnings, $300,000 per month. Its a free dating website. Here is a picture of the check from adsense.
About three months worth of Adsense rev. in canadian dollars. It is especially interesting because in August 2003, the site was making about $40/day from 1200 visitors.
(ii) Digg.com : Adsense earnings – $250,000 per month. No surprise here.
(iii) ShoeMoney.com: Adsense earnings – $150,000 per month.
(iv) Weblogs, Inc (Engadget.com and other websites): Adsense earning $120,000 per month.
(v) Freeweblayouts.net : Adsense earning $100,000 per month.
There are several other sites that make $50k per month from the adsense earning (podcastdirectory, askthebuilder.com, etc)
The rule of thumb seems to be $0.02 earning per page view.
I really would have preferred for the content providers to be compensated by micro payments and I am still hopeful that Google will lead the way in implementing it.