Originally posted by: Locut0s
"The typical visitor buys from tomshardware.com and reads techspot.com."
Accuracy??? Where do they get their facts from?
We Start With Panel-Based Data
Most rating firms estimate web audiences the same way radio audiences were estimated 70 years ago: by surveying a sample of people and extrapolating to the larger audience.
Our estimates start the same way, with a panel of several million people who anonymously share their web usage history with us. Using statistical techniques we project which sites the rest of the U.S. web audience is visiting and publish basic profiles reflecting those estimates.
Unfortunately, panels aren?t perfect. Panels have biases, and with millions of destinations on the Web, even a panel as large as ours can?t do justice to niche audiences. So our analysis doesn?t end there.
Directly Measured Data
With publishers? cooperation, web visits can be counted directly and accurately. Our Quantified Publisher program enables publishers to tag their sites and services for measurement free of charge. We can then gauge the actual reach, frequency and popularity of their websites, videos, widgets, games and more.
Direct measurement isn?t perfect either. Web logs ultimately measure page views, not people. Because of technical challenges like cookie deletion, it?s hard to know how many actual people are visiting, much less to get any insight about ?who? they are. So we?re still not done.
http://www.quantcast.com/docs/how-quantcast-works
sounds like a load of shiet