Quantcast Products and Services Privacy Policy (RETIRED December 15, 2022)

This Quantcast Products and Services Privacy Policy was retired December 15, 2022. View the current Quantcast Products and Services Privacy Policy.

Effective: December 9, 2020

Privacy Commitment

We care about your privacy and want you to be informed about what we do. This Privacy Policy explains how we collect, use, and share the information we receive about our clients and consumers, and explains the options that are available to you. We’ll try to make this all as clear and as simple as possible, but if you have questions, you can contact us, and we’ll be happy to help. (See the “Contact Us” section below.)

What We Do

We have two main product suites: (1) Quantcast Measure and (2) Quantcast Advertise. Our Measure products help website owners to understand the interests and demographics of the people who visit their sites. (Here’s an example.) Our Advertise products allow businesses to deliver relevant online advertising to individual consumers. For companies that want to advertise online, our Advertise products help get their ads in front of the people that are more likely to find them interesting. For consumers, we provide ads that are more useful and relevant to their interests. And for websites, our Advertise products help drive advertising revenue, without which the free Internet we all use every day would not exist. In short, we try to make online advertising more efficient and pleasant for everyone. In order to do all this, we collect and analyze information about individual consumer interests and demographics.

We also offer Quantcast Choice, a consent management tool for publishers and advertisers built on the IAB Europe Transparency & Consent Framework that helps website operators provide consumers with information and choices about data. From time to time, we may offer additional products.

You can read more about how our services work in our FAQ.

Scope of This Privacy Policy

This Privacy Policy covers the information that we collect or receive from across the Internet and mobile space through our products and from registered users of our products. We may change this Policy from time to time (see Changes to the Privacy Policy section below). If you are interested in our collection and use of data in relation to this website and other corporate functions, click here.

Some Helpful Terminology

We use some phrases in this Privacy Policy that are unique to our business or the online advertising industry. Here are some of the key terms that you’ll need to know to make it easier to review this Privacy Policy.


A cookie is a small file containing a string of characters that is sent to your device when you visit a website. Cookies typically are used to store user preferences or IDs and are generally associated with a browser. See our FAQ for more information about cookies and how they work. You do not have to use cookies, but if you do not accept cookies, you may not be able to use all features of a website you are visiting or all functionality of the Services (as defined below).


A tag is a tiny snippet of code inserted into a Partner’s website content that is used to collect data related to a website visit. Similar functionality is enabled in a Partner’s mobile app through the use of an SDK (Software Development Kit). When a user views a Partner’s website or uses a Partner’s app, our servers are notified, and we are able to collect information from the browser or application. See our FAQ for more information about our Tags and SDKs.

Log Data

Log Data includes (1) information sent to Quantcast by browsers that encounter our Tags, including, for example, browser type, browser time, time of access, screen resolution, IP address, referring site URL, current site URL, and search strings; (2) information sent to Quantcast by advertising exchanges in the form of bid requests, which may include the information above as well as information like auction identifiers, for the purpose of soliciting bids to place online ads; and (3) information received from the Quantcast SDK embedded in mobile apps, which may include the above as well as information like mobile advertising identifier, location information, application data and usage information, and unique application and installation identifiers.

Personal Information

Personal Information (also sometimes called “Personal Data”) is information that is associated with an individual and may enable that individual to be directly or indirectly identified. Through the use of our tags, SDKs, and cookies, we collect Personal Information about you; the Personal Information that Quantcast collects does not include information that may be used to identify you directly (for example, Quantcast does NOT collect your name or email address). However, Quantcast does collect information that may indirectly identify you. Some information transmitted by Cookies and Tags including Log Data are Personal Information. Quantcast may also receive some information about you from third parties and we may combine such information with personal information we collected about you ourselves. However, while we make predictions about your interests and demographics based on this information, we do not know who you are. For more information about the Personal Information that we collect, please visit our FAQ page

Quantcast Partners (“Partners”)

Our Partners include the site operators and mobile application developers that request that we collect information about the visitors to their sites and users of their apps through our products.

Our Partners also include companies that we work with to provide the Services.

For more information about our Partners, including what types of partners we have and what types of data we share with them, please visit our Partners page.

Quantcast Services (“Services”)

This term refers broadly to the entire set of services that we provide through our products, including the collection of Personal Information, the analysis of that information, the provision of that information and insights derived from that information to or for our Quantcast Partners, and the selection and placement of optimal advertisements and content based on that information.

Information Collection and Use

Legal Bases for Collection and Use

In order to deliver our Services, we use the information described in this Privacy Policy as necessary for our legitimate interests, unless those interests are overridden by your interests or fundamental rights and freedoms that require protection of Personal Information. Our legitimate interests include providing, improving, and customizing the Services offered to our Partners and providing you with relevant advertising and content. We may share your information (as described in this Privacy Policy) where necessary to pursue our legitimate interests and those of our Partners in serving more useful and relevant advertising. You have the right to object to our use of your Personal Information to pursue our legitimate interests, which is described in the How To Object and Opt Out section below.

In addition, where you have given us consent to use your information in certain ways, we will rely on your consent to process the information. You may revoke that consent at any time. Please see the How To Object and Opt Out section below for information as to how you may withdraw your consent.

Information Collected through our Services

When you visit a site or app operated by a Quantcast Partner, the Partner permits Quantcast to collect Log Data from their sites and apps through the use of Tags and Cookies; we also receive information directly from our Partners. We associate this information with a unique random identifier associated with your device (like a cookie ID), but we never associate it with your name, email, address, or phone number, because we don’t collect that type of directly identifying information about consumers. We use this information from Partners, which includes information about some of the sites you are visiting and some of the apps you are using, as necessary for our legitimate interests to help improve the accuracy of our products and to determine what advertisements and content might be interesting to you. For example, if you were recently searching for plane tickets to San Francisco, we might predict that you are interested in purchasing a nice warm sweater, and then show you an ad from one of our Advertising clients that sells sweaters. (To be more precise, we would predict that your device might belong to a person interested in sweaters, because we don’t know who you are.)

We do not link Log Data to your name, address, email, or phone number, or otherwise attempt to discover your identity. We employ appropriate organizational and technical security safeguards to keep information about you secure and to make it difficult for us to associate it with your identity.

When you visit a site or app that uses Quantcast Choice, we may use tags, cookies, SDKs, and plug-ins to store information about privacy notices that you have received and privacy choices that you have made. We do this pursuant to the IAB Europe Transparency & Consent Framework’s policies and technical specifications. We do not use any information collected from Quantcast Choice for other purposes. In other words, we do not use that information to inform our Measure and Advertise products outside of understanding the privacy notices you have received and privacy choices you have made.

Information Sharing and Disclosure

Information Shared with Our Partners

We share with third parties certain information, including Log Data, as part of providing and improving our products. For example, we disclose some of this data to companies involved in ad delivery or ad viewability. Likewise, we disclose some of this data in order to provide or facilitate site audience measurement, traffic analysis, or demographic analysis, and to enable websites to provide their advertisers with audience segments that are appropriate for their products or services. Since, as described in this Privacy Policy, we do not intentionally collect directly identifiable information about consumers (like your name or email address), we don’t share this type of information with Partners. To learn more about information that we share with our partners, please visit our Partners page.

Information Shared with Our Service Providers

We use third parties and Quantcast partners to help us administer and improve our products. For example, these companies assist with hosting, data processing, database management, and administrative tasks on our behalf. These third parties and partners have access to information about you, including through the placement of Tags on our Site, to perform these tasks on our behalf. To learn more about service providers for consumer information, please visit our Partners page.

Information Disclosed for Our Protection and the Protection of Others

It is our policy to protect you from having your privacy violated through abuse of the legal system. We reserve the right to disclose information about you to government or law enforcement officials or private parties as we, in our sole discretion, believe necessary: (i) to comply with any applicable laws, regulations, and valid subpoenas, warrants, and court orders; (ii) to protect the rights, property, and safety of ourselves, third parties, or the public in general; and (iii) to prevent or stop activity we consider to be illegal or unethical.

Information Disclosed in a Change of Ownership

Quantcast may sell, transfer, or otherwise share some or all of its assets, including information we collect about you, in connection with a merger, acquisition, reorganization, or sale of assets or in the event of bankruptcy. We may also make certain information available to a potential investor or purchaser (and their advisers) in advance of any such transaction completion.

Cross-Platform Associations

We provide a cross-platform reporting service to Partners that operate both websites and mobile apps. To accomplish this, we rely on hashed (i.e., scrambled) identifiers derived from user logins to associate your usage across mobile and desktop platforms. This allows our Measure product to provide meaningful reports across platforms for a single Partner. We also sometimes use Log Data or other data from our Partners to make guesses about associations between devices or platforms.

Data Retention

We retain data for as long as necessary to provide our Services and for the purposes described in this Privacy Policy. For example, we retain Log Data for up to 13 months. It is then permanently deleted. We may also retain information as is necessary to comply with our legal obligations, to resolve disputes, or to enforce our agreements.

How to Object and Opt Out

If you prefer not to receive interest-based content and ads enabled by Quantcast, you can object and opt-out by clicking on the Quantcast “Opt Out” link here. Additionally, we are a member of the Network Advertising Initiative (NAI) and participate in the Digital Advertising Alliance’s (DAA) Self-Regulatory Program. Each of these programs provides an opt-out feature where consumers can choose not to receive targeted advertising from any NAI or DAA affiliate. These links will take you to the NAI opt out and the DAA opt out. If you are located in the European Union, you may prefer to use the EDAA opt out. If you choose to opt-out, we will place a cookie on your device which is associated with your browser that identifies you as having opted out. Then you will not receive interest-based content or advertisements enabled by Quantcast and we will not log your website visits or other online media consumption. Because our opt-out is cookie-based, your browser must be set to accept third party cookies. If you use multiple devices or browsers, you’ll have to opt out on each. If you delete the opt out cookie, you will need to opt-out again.

Where you have provided Quantcast with consent to use your data, you may revoke that consent at any time. Where you have used Quantcast Choice to provide your consent to Quantcast or other vendors, you may visit the website where you gave that consent at any time to update your choices.

Accessing, Changing, or Deleting Your Information

If you are a registered user, you may review, update, correct, or delete the information in your registration profile by logging into your account. If you want to delete your account, please contact us.

If you are located in the European Economic Area (EEA) and we can properly identify you, you have a number of rights with regard to your Personal Information. For example, you have the right to access your information and to have inaccuracies in your Personal Information corrected. In many cases where we process your information, you may also have a right to restrict or limit the ways in which we use your information. You also have the right to object to the processing of your Personal Information and to have it deleted in certain circumstances. You also have a right to obtain a copy of your Personal Information in an easily accessible format. For these purposes, go here.

However, as outlined above, although we make predictions about consumers’ interests based on the information collected in accordance with this Privacy Policy, we don’t collect, determine your identity, or know who you are. Accordingly, if we receive a request from you and we cannot identify you (even if you provide us with additional information), we may not be able to assist you in exercising these rights.

Data Security

We employ administrative, physical, and technical measures designed to protect the confidentiality and integrity of Personal Information that we store. These measures may include encryption and employment of information storage security technologies to restrict access to our network. Please be aware that no method of transmitting information over the Internet or storing information is completely secure. We have procedures and security features in place to help keep your data secure once we receive it. Additionally, in some instances our Partners or others may provide information to us in unencrypted form.

International Transfers

Quantcast operates a global service. Your information is transferred internationally between Quantcast affiliate companies and our Partners to countries around the world including the United States, where the privacy and data protection laws may be different than those in your jurisdiction. We use standard contractual clauses approved by the European Commission, and may rely on the European Commission’s adequacy decisions about certain countries, as applicable, for data transfers from the EEA to the United States and other countries. You can contact us to request a copy of our Standard Contractual Clauses.

Our Policy Toward Children

Quantcast does not knowingly collect or use data from children under 16. If a parent or guardian becomes aware that his or her child has provided us with Personal Information, that parent or guardian should contact us. If we become aware that a child has provided us with Personal Information, we will delete such information from our files.

Health and Sensitive Information

Quantcast does not knowingly collect or utilize any sensitive health-related information, such as, for example, information related to past or present sensitive medical conditions or prescriptions. We provide a list of standard health segments and a representative sample of custom health segments used by Quantcast for the purposes of Interest Based Advertising. Please note that in certain jurisdictions the creation and use of health segments by Quantcast is restricted in line with legal and/or self-regulatory requirements. In the EEA, Quantcast does not knowingly collect or utilize any Personal Information revealing racial or ethnic origin, political opinions, religious or philosophical beliefs, or trade union membership, genetic or biometric data for the purpose of uniquely identifying an individual, or data concerning an individual’s health, sex life, or sexual orientation, as well as Personal Information related to criminal convictions and offenses.

Other Websites and Apps

We contractually require our Partners that use Quantcast Tags and SDKs to attest that their sites and apps containing Quantcast Tags and SDKs post adequate privacy policies and otherwise protect the privacy rights of their visitors. However, the fact that we link to, receive data from, or partner with a particular site or app does not mean that we endorse it or its privacy practices. These other websites and apps have their own terms of use and privacy policies, and we would encourage you to read those terms and policies when you visit those websites and use those apps.

Quantcast Data Control

The Quantcast Site and Services are made available and provided to persons residing within the United States by Quantcast Corporation, located at 795 Folsom Street, San Francisco, CA 94107. Information or data relating to persons within the United States provided to or gathered by the Quantcast Site or Services is controlled by Quantcast Corporation.

The Quantcast Site and Services are made available to persons resident outside the United States by Quantcast International Limited, located at Beaux Lane House, Lower Mercer Street, 1st Floor, Dublin 2, Ireland. Information or data relating to persons resident outside the United States provided to or gathered by the Quantcast Site or Services is controlled by Quantcast International Limited.

Our Memberships and Affiliations

Quantcast is an active member or participant of industry associations that govern the policies around online consumer privacy in the context of internet-based advertising, including: the Network Advertising Initiative (NAI), the Digital Advertising Alliance (DAA), and the European Interactive Digital Advertising Alliance (EDAA). Quantcast complies with the NAI Code of Conduct, the DAA Self-Regulatory Principles, and the EDAA Self-Regulatory Principles. We believe that these codes and principles help protect consumer privacy.

Please see the “Opt Out” section of this Privacy Policy for more information about the NAI’s, DAA’s, and EDAA’s opt-out pages.

Quantcast participates in, and complies with the policies and technical specifications of the IAB Europe Transparency and Consent Framework, as both a consent management platform (CMP) and a vendor. Quantcast’s IAB Europe-assigned identification numbers are CMP ID #10, and Vendor ID #11.

Information for California Residents

In addition to the information, controls and rights detailed in this privacy policy, California law provides for specific rights for California residents. California residents may request access to Personal Information, request a copy of their Personal Information, or request that their Personal Information be deleted. You may submit a verifiable request through Quantcast’s Data Subject Rights page, which can be found here. California residents may also submit verifiable requests by contacting Quantcast via email privacy [at] quantcast [dot] com. Consistent with California law and to provide for the security of Personal Information, Quantcast will verify requests from California residents, as well as requests received from authorized agents acting on behalf of California residents. Information about annual data requests is available here.

Changes to the Privacy Policy

Any information that we collect is subject to the Privacy Policy in effect at the time that information is collected. We may revise this Privacy Policy from time to time, so please check this page regularly for updates. If we make any material changes to this Privacy Policy, we’ll notify you of those changes by posting them clearly on our website and/or by sending you an email or other notification, where feasible, and we’ll indicate when such changes will become effective.

Contact Us

If you have any questions about this Privacy Policy, please let us know.

Persons in the United States, please contact:

Quantcast Corp.

795 Folsom Street

San Francisco, CA 94107

Email: privacy [at] quantcast [dot] com

Persons outside of the United States, please contact:

Quantcast International Limited

Beaux Lane House

Lower Mercer Street, 1st Floor

Dublin 2, Ireland

Email: privacy.qil [at] quantcast [dot] com

The Data Protection Officer for Quantcast International Limited can be contacted dpo [at] quantcast [dot] com.

If you have contacted us or our Data Protection Officer about a privacy or data use concern and feel that we have not addressed it satisfactorily, you may contact our US-based third party dispute resolution provider (free of charge) at https://feedback-form.truste.com/watchdog/request.

If you are a resident of the EEA, you also have the right to lodge a complaint against us with our lead supervisory authority, the Irish Data Protection Commission, or your local supervisory authority in the country in which you reside.