Privacy Implementation for Quantcast Publisher Partners

Last Update: March 18, 2022 

This Document is for Quantcast publisher partners and clients who include Quantcast code, such as pixels or tags, on their websites for Quantcast Measure or the Quantcast QID Module in Prebid. It allocates privacy-related responsibilities to ensure that users’ rights are honored with respect to data processed by Quantcast’s services. 

Privacy regulation around the world is dynamic. Quantcast may update this document from time to time at its own discretion in order to keep pace with changes in privacy rules and risks, and industry best practices, as well as to ensure users’ rights are honored appropriately. 

Quantcast may take reasonable measures to ensure that data processed in its services is collected and processed in accordance with privacy rules and industry best practices. We may review locations where data is collected and may refuse to accept data that is not collected in a manner consistent with the approaches described in this document.  

This document does not contain legal advice, and adherence to this document does not ensure legal compliance. Publishers must ensure for themselves that they operate in a legal manner, based on their particular circumstances. In the event of any conflict between this document and applicable laws or regulations, the laws or regulations should prevail.


This document uses “user” or “users” as interchangeable with “data subject” or “consumer” or other equivalent terms from various rules. 

When we say rules, we mean laws, regulations, and industry self-regulatory codes that are applicable to the processing of personal data in relation to Quantcast’s services. Quantcast has a global footprint, including operations in Europe, the UK, and California, so those jurisdictions’ rules are applicable to Quantcast for data about users who reside in those jurisdictions.  

We also will use “personal data” as interchangeable with terms such as, “personal information.” Personal data processed by Quantcast’s service is pseudonymous, including but not limited to IP address, cookie or device IDs, and other identifiers used for advertising-related purposes. In the case where a publisher has express permission from Quantcast to use email address, phone number, or other directly identifying information, such information will be pseudonymized (usually hashed or encrypted,) according to Quantcast specifications, before transmitting to Quantcast.

Industry standards and self-regulatory programs

Quantcast supports and participates in industry self-regulatory programs, and generally implements industry standards and best practices when it comes to handling personal data. Publishers are responsible for ensuring their own implementation of self-regulatory rules and industry best practices, in particular related to providing transparency and choice to users in places where data is collected or used by Quantcast’s services. 

Controller, processor, service provider, vendor, etc.

Unfortunately, terms used across jurisdictions that describe the relationships between parties sharing data are not interchangeable. Quantcast determines its role based on applicable law and the facts of its processing of personal data.

Publishers: Where the GDPR applies, Quantcast is a controller of personal data collected using Quantcast tags and pixels dropped on your sites. This document, together with the Quantcast agreement under which you access our services, addresses our respective GDPR compliance responsibilities. Where the CCPA applies, Quantcast acts as a third party. 

Notice/Transparency and Choice

Laws, self-regulatory rules, and industry best practice require users be notified about processing of personal data, and be offered a choice – either opt in or opt out — with respect to that processing. 

When deploying Quantcast tags or pixels, including Quantcast Measure tags and the QID prebid module, publishers are responsible to make sure that users are given notice and choice that is required for Quantcast to be able to collect and process the data. And, of course, publishers have to make sure of notice and choice for their own collection and processing of personal data.

At minimum, and further subject to any other applicable laws or rules, notice must include the fact that third parties are collecting and processing users’ data, along with information about the data collected, the means of collection, the purposes for processing (including interest-based advertising and advertising measurement), and access to choice. Laws or rules in some jurisdictions, including GDPR jurisdictions, would require that Quantcast be specifically identified in the notice, and a link to Quantcast’s privacy policy be included. 

Quantcast’s methods of collection include, depending on particular circumstances, cookies, pixels, JavaScript tags, probabilistic device matching and cross-device matching (using passively collected data). Details about Quantcast’s cookies. The data Quantcast collects includes information about users’ visits to sites, such as IP address, device information, timestamp, referrer URL, etc. 

Quantcast implements choice using industry standard methods, and will be responsible for honoring that choice with respect to personal data within Quantcast’s services. 

For their part, publishers need to provide access to the choice using industry standard and legally compliant methods, depending on the applicable laws and rules. Publishers should, at minimum, and subject to any additional, legal, requirements provide a link to the geographically relevant industry opt-out page, including but not limited to YourAdChoices and the NAI in the US, Your Online Choices in Europe, and Your Ad Choices Canada.

In all cases, publishers should have user-facing privacy policies that are prominently linked from their homepages and from content (sites, apps, etc.) where personal data are collected or used. 

Privacy policies will adhere to applicable laws, as well as industry self-regulatory requirements and industry best practices. At minimum, policies should disclose the fact that third parties are collecting personal data for advertising-related purposes, and should describe the methods of collection, as described above. Particular circumstances and applicable rules may create additional requirements.

Where consent (opt-in) is required prior to setting cookies or collecting data, such as in Europe under ePrivacy and the GDPR, publishers are responsible to make sure that tags or pixels don’t fire until that consent is obtained. Publishers must not send to Quantcast, or enable Quantcast to collect, personal data without having established required permissions, and certainly not if the user has explicitly opted out.

Europe and the UK: The industry standard means for ensuring notice and choice for vendors like Quantcast in Europe and the UK is the IAB Transparency and Consent Framework. Quantcast is vendor ID 11. Quantcast’s required purposes and associated legal bases are viewable in the Global Vendor List. Because Quantcast is subject to European law, the TCF should be used for all users in Europe or the UK, even if the publisher has no operations in Europe. Alternatively, such publishers may elect not to introduce data about European or UK users into Quantcast’s services. Quantcast Choice is a leading, and TCF compliant, Consent Management Platform. Proper use of Quantcast Choice will meet these TCF requirements.

Publishers not using the TCF for European or UK users may, only with Quantcast’s express written permission, use a legally compliant alternative means to ensure Quantcast’s legal basis for using cookies, where applicable, and for processing the data. This includes that Quantcast must be identified as a controller of the user’s personal data, and a link to Quantcast’s privacy policy must be provided. Quantcast may in the future require TCF. In any case, publishers should not allow data to be collected by, or transmitted to, Quantcast on their sites without user consent, and must be able to provide proof of consent to Quantcast, upon request. 

Privacy policies in Europe and the UK need to include a link to the European Digital Advertising Alliance (EDAA) opt out page, located at

US: In the US, along with other requirements laid out here, privacy policies need to include links to an industry standard opt out page, like the NAI or DAA. 

California: The CCPA applies for users in California. Publishers need to provide notice of selling and access to the right to opt out, as required. Quantcast does not sell data that it collects or receives from publishers’ sites. Unless agreed otherwise with Quantcast, Quantcast acts as a third-party, as defined under the CCPA, for when it collects data from publishers’ sites. Quantcast will check the US Privacy String, as specified by the IAB.

Access and Deletion

Under the GDPR, Quantcast will be responsible for providing users access and deletion with respect to their personal data that is within Quantcast’s services that Quantcast is a controller over. 

Under and as required by the CCPA, when acting as a service provider, Quantcast will cooperate in honoring access and deletion requests. Note that data is regularly aged off as part of the normal function of the services. 

Other Matters

Sensitive data. Because Quantcast’s services are not intended for processing sensitive or special category data or data about children, publishers must not transmit to Quantcast or cause Quantcast to collect any such data. Quantcast tags and pixels may not be deployed on content that is directed at children. Sensitive or special category data includes data defined under Article 9 of the GDPR, Section 1798.140 of the CCPA (as amended by the CPRA), or any equivalent term under applicable law. Directly identifying personal data. Quantcast’s services are not designed to process directly identifying personal data, such as names or email addresses, and publishers may not send such information to Quantcast or cause Quantcast to collect it. If a publisher has express permission from Quantcast to use email address, phone number, or other directly identifying information, such information will be pseudonymized (usually hashed or encrypted,) according to Quantcast specifications, before transmitting to Quantcast.