Among the websites I enjoy best, I probably provide the most revenue to Amazon.com. I spend several hundred dollars a year there, easily, and the more I come into money, probably the more I will spend there. A lot of the page views I do there turn into adding books to my wish list and eventually to my shopping cart, so the company is monetizing my browsing behavior pretty well. On the other hand, the company has to maintain warehouses and a physical inventory and pass through shipping costs, so not all of its considerable implicit revenue per page view turns into earnings per page view.
At another extreme, Hacker News gains no revenue whatsoever from my browsing behavior. It may gain for Y Combinator some kind of business reputation value insofar as I would be very likely to recommend an application for YC seed funding to any young entrepreneur who develops out of my math coaching program, and to my own children, but chance for YC to invest in the next great start-up as a result of my browsing here is quite speculative, to be sure. But then again it doesn't cost HN as much in server hardware or staff time to curate the site to draw me in for lots of page views as it does Amazon.
Where do your favorite sites fall between these extremes? (Do you have even more extreme cases among your favorite websites?) How many websites you read regularly appear to gain net earnings from your browsing behavior?