Quantserve (Quantcast): What is it and what does it do?

For an introduction to cookies and web trackers, read our guide.

What is Quantserve?

Quantserve.com creates web beacons and cookies operated by audience research and behavioural advertising company Quantcast.

It has a number of products:

Measurement & Insight
This service allows website owners and advertisers can use Quantcast web beacons in their content to see how many views they get, what age range the people viewing are likely to be in, and what income they are likely to generate (demographic data).

Audience Targeting
Quantcast uses the measurement and insight data help companies find people to target with their advertising. Their "Quantcast Lookalikes" service lets website owners build their own audience segments, which can be very specific. For example, a company could build a behavioural profile of the type of person that likes buying a particular product from their website. Quantcast would then identify other browsers that are similar so adverts for that product could be targeted to them.

What information is Quantcast tracking?

Quantcast says all its tracking is anonymous, accessing when, from where and at what time a browser loads its web beacon. "Quantcast only models anonymous records of internet usage. Quantcast does not intentionally collect any personally identifiable information – that is, information that could be used to uniquely identify or locate an individual."

On its website, Quantcast says it uses statistical modelling to "build a translation of cookies to people". Part of the aim of this approach is to counteract the issue that some people who access sites on multiple devices, or delete cookies regularly, may be counted more than once.

Quantcast say it does this by looking at patterns such as how often browsers are visiting the site, and how often they are likely to visit at home and work to infer how many "real" people are accessing a website.

However, it does not obtain information that relates back to specific individuals. What Quantcast does is build up a profile of a browser's behaviour across all sites using their web beacons (it claims these include over "100m web destinations, including websites, video, widgets, blogs, and advertising campaigns").

Information that may be captured when browsing a site using Quantcast includes: what page the browser was on; what searches were typed into the website search; the time the browser was on the website. This information, or "log data", is then used to build a profile of different types or "segments" of browsers.

In 2010, Quantcast paid $2.4m to settle a class action lawsuit alleging it used Flash cookies to reset tracking cookies after users deleted them. The firm stopped using Flash cookies in 2009, after research by The University of California Berkley identified the practice and it was publicised in the media.

Is the data sold to third parties?

In its privacy policy, Quantcast says it may share log data and aggregated information with third parties. These include:
- companies employed to support Quantcast services.
- companies that provide delivery and measurement of ad campaigns.

This data would be used for such things as industry analysis and targeting adverts.

How much money does Quantcast make?

Quantcast is a private US company so is not obliged to publish detailed breakdowns of its revenue and profit. However, the company does say it is backed by over $50m in funding from the following investors: Allen & Company, Cisco Systems, Founders Fund, Polaris Venture Partners and Revolution Ventures

Further reading:

• Evidon factsheet on Quantcast
• Quantcast Privacy Policy
• Quantcast Opt-Out Page
• Quantcast: Cookie Corrected Audience Data — White Paper (PDF)
• University of California Berkley research paper on Flash cookies

ncG1vNJzZmivp6x7tbTEoKyaqpSerq96wqikaKyVmLWvu8uonrJnYmV%2Bc3vAqaloamNkvratza2amqukYsGzrcKkoKefXam%2Foq%2FKnqmsZZOkvKy1xKxksJ2SYrqwusitpquhnpw%3D