They call themselves "The World's Only Open Internet Ratings Service." The big departure from history for Quantcast is that they are a "census-based" service rather than sample-based. What does this mean? It means that they are able to go much deeper in number of sites rated than the commercial services such as comScore and NetRatings. In fact, they "see" over 20 million sites as compared to the low 10s of thousands for other services. In the digital world where audiences may be small and we still want to slice and dice them for targeting, census-based sources may be the only way to go.
In a Google-like move, Quantcast at this point is a free service to all, both for publishers and for agency planners and buyers. More about that below.
Quantcast starts with a methodology similar to other rating services in the fielding of a panel with several million self selected respondents. They then use statistical techniques to project to the total U.S. That's when it gets interesting. They also have the capability to put their tags on publisher sites (with publisher permission) that can get much more granularity out of the information. They then combine the two of these methodologies and use their "secret sauce" called a Mass Inference algorithm to produce refined Web audience profiles. These algorithms have been ported over from the finance industry and refined by mathematicians recruited from NASA and other high-end organizations.
As I mentioned above, publishers must put Quantcast tags on their site to "Get Quantified" and ensure that the best possible information about their site is presented. In discussing this process with publishers, I have found that most find that their Quantcast audience to be higher than that reported by either comScore or NetRatings and closer to their log file reports. When publishers ask me if they should do this, my reaction is always, "Why wouldn't you do it?" It's free and Quantcast is going to report on the site anyway. So why not do everything they can do to make the data as representative of their true audience as possible?
Agency planners and buyers are using the tool, too. At Mediasmith, our planners have found it to be a quick way to determine if a site they are not familiar with skews towards a clients' target and is a candidate for further consideration. It also uses Domain Tools thumbnails to assist in getting a quick snapshot of the site. More powerful agency planning tools are on the way shortly. In time, they will be able to provide us information on those engaging with our ads and how those demos differ from the sites those consumers are on.
Their end game is not yet transparent. But it is clear that this is more than just a rating service. Quantcast's ability to measure targets puts them in the position of being a next generation Tacoda, with or without a network attached. They should be able to provide us with much more than behavioral information, given that they have an increasing amount of demographic and sociographic information on consumer web patterns.
To get to the big time, Quantcast needs to achieve greater distribution among top sites in their Quantified Site program. They are making great progress, though, with top sites like Newsweek, People.com, Digg and NBC already participating. They have an active business development program and are in conversation with many top sites.
So check it out today and keep an eye on their progress. This is a tool that will only have greater and greater utility as time goes on.