Do you have a blog? If you do, then I’m sure that you know how many visitors you have. There are so many free tools which measure traffic, that it is hard to believe that you did not grab at least one and put it at work on your blog. For instance, on this blog I use four tools: Google Analytics, Statcounter, 103bees and AddFreeStats. But do you know who your readers are? How old are they? What household income do they have? What education do they have?

Quantcast, a San Francisco company, seems to have the answers. Launched in September 2006, Quantcast is managed by a team of experts in statistics technology and web analytics, and it offers a free service of open internet ratings.

“Quantcast is the world’s first open internet ratings service. Advertisers can find reports on the audiences of millions of web sites. Publishers can ensure their sites are represented accurately by tagging them for direct measurement. The service is free to everyone.”

One of the most important factors is data collection. There is not much info available, in this respect.

“We collect our data through affiliations with partners, who include advertisers, publishers, ISPs and advertising networks. All the data we collect is anonymous and contains no personally-identifiable information.

Anyone can participate. Web publishers can obtain refined analysis on their site by utilizing a Quantcast measurement pixel. If you want to help make Quantcast’s analysis even more accurate then please become a Quantified Publisher.

What information do you collect?

We observe anonymous records of visits to internet destinations. For a portion of these observations, we have certain information, such as the age, gender or income level of the internet visitor and/or their household. This group is called a panel and forms one aspect of our analysis and reporting methodology. We also analyze internet log records which include information such as the page viewed and the IP (internet protocol) address used to access the page.”

Quantcast claims to take care of personal privacy. All analysis use anonymous internet usage information.

If Quantcast data prove to be accurate, advertisers will have an invaluable targeting tool for their online campaigns.