Quantcast Methodology FAQs
- How do you collect your data?
- What is a cookie?
- Why might the number of cookies and people be different?
- How big an impact do cookie deletion and multiple machine use have?
- How does Quantcast deal with cookie deletion, and translation to people?
- Why has Quantcast implemented cookie correction to its Quantified publisher traffic data?
- What data has changed on the site as a result of cookie correction implementation?
- I rely on Quantcast’s cookie data for business and programming analysis, is it still available?
- Why do non-Quantified sites only provide people-based data counts, and no option to view cookie counts?
We collect directly-measured data from the millions of web destinations controlled by our Quantified publishers. All the data we collect is anonymous and contains no personally-identifiable information.
Anyone can participate. Digital media publishers can obtain refined analysis on their site by measuring their web properties utilizing a Quantcast measurement pixel. No matter how large or small your potential audience, Quantcast can provide a more detailed understanding of the size and demographic characteristics of your digital media content.
A cookie is a small text file that your browser uses to identify you to individual sites. It might be used to automatically log you in to your web-based email, or store personal preferences on your favorite news site. Cookies are also used to aggregate statistics on website activity levels. Quantcast uses cookies as part of its audience measurement process.
Why might the number of cookies and people be different?
As text files, cookies may be deleted from time to time. If the cookie for a particular website is deleted between visits, a browser is issued a new cookie upon its return. In such cases, the website will have recorded two cookies for the same individual browser and the resulting cookie count is actually larger than the number of browsers that have visited the site.
Adding complexity to this problem, while many people may use the same browser to access a website, others may use multiple browsers or machines (at home and work, for example) to access the same website. This creates a more complicated environment and is why Quantcast has developed a sophisticated model to deal with cookie deletion and multiple machine usage to produce accurate estimates of the number of people that visit web destinations.
How big an impact do cookie deletion and multiple machine use have?
The impact of cookie deletion and multiple machine use/people use per machine is not uniform and differs significantly between sites. In some cases, though, it is not unusual to see an average of two (or more) cookies for every browser over the course of a month. A variety of factors must be taken into account to properly adjust property level translations from cookies, to people. Quantcast has issued a Cookie Corrected Audience White Paper which discussed many of the considerations we factor into our model. At a high level, these include time period of evaluation, frequency of visit of user, cookie deletion rate and machine use behavior of a specific properties audience.
How does Quantcast deal with cookie deletion, and translation to people?
At Quantcast we have access to multiple complementary data sources. We have several clickstream data sources which allow us to calibrate our cookie correction models. Our Quantcast Publisher program captures over 175 billion media consumption events every month, generated by more than 2.3 billion cookies (data as of June, 2009). What’s more, many of our Quantified publisher partners share anonymous identifiers with us that are independent of cookies. This mass of data – with different collection processes, biases and issues — allows us to effectively “triangulate” and develop dynamic, and accurate projections. Learn more about how our model works.
Why has Quantcast implemented cookie correction to its Quantified publisher traffic data?
While cookies provide valuable learning related to traffic flow on a site, they do not provide the people-based insights that advertisers demand. We believe facilitating a view of both cookie and people-based intelligence is a critical advancement that will enable addressable advertising.
What data has changed on the site as a result of cookie correction implementation?
Prior to our cookie corrected model launch (June 23rd, 2008), Quantified publishers had unique cookie data reported as their default traffic count. This data was included on site profiles, and in our recently released Quantcast Planner tool. All Quantified publishers now have people counts reported as their default traffic count, across all components of our service.
I rely on Quantcast’s cookie data for business and programming analysis, is it still available?
Absolutely. You can continue to access cookie data on the detailed Traffic Tab. Just select the “cookie” tab on the traffic chart to switch from people to cookie counts.
Why do non-Quantified sites only provide people-based data counts, and no option to view cookie counts?
Cookies are directly measured. Quantified publishers, by nature of their active participation in Quantcast’s service, have this data collected and reported. We do not track census level cookie data for non-Quantified publishers, and as such, do not provide this data. If you are a publisher, and would like improved audience data to be reported for your property, simply register for our free measurement tool.
