AppNexus Publisher Suite

AppNexus helps the world’s top publishers fully monetize their content through integrated ad serving and programmatic selling solutions.

AppNexus for Agencies / Advertisers

AppNexus helps brands connect with consumers, empowering agencies and advertisers with a uniquely powerful approach to programmatic.

AppNexus for Ad Tech Companies

Ad Tech and media companies use AppNexus to power value-add enhancements for marketers and publishers.

Sign In

Products for Agencies / Advertisers

Products for Ad Tech Companies

Platform Privacy

For information regarding our corporate website privacy practices, please click here.

This information and the privacy statement below apply to our online advertising technology platform (the Platform) and its use by and on behalf of our clients, and will be of general interest to Internet users. Our goal is to be transparent to Internet users about our business by describing our business in simple terms that Internet users can understand. If you have any questions about this information, or would like more details, please contact us here.

The platform is operated by AppNexus Inc., 28 W 23rd Street, 4th floor, New York, NY - 10010, USA.

Opt Out: To go directly to our opt out, click here


Ad Server: An ad server, in its simplest form, is responsible for delivering an ad to be shown in a web page or a mobile app. Today, communications may be sent to several servers in the process of selecting and delivering an ad. This occurs in a matter of milliseconds. 

Beacons, Pixels, and Tags: Beacons (also sometimes referred to as web beacons or pixels) and tags enable online advertising companies to collect data, serve advertising, and provide related services, such as measurement or fraud prevention, on web sites by allowing communication between a web browser and a server. A beacon is a small transparent image that is placed on a web page. A tag is a small piece of website code that is run by the web browser. 

Mobile SDK: A mobile SDK is the mobile app version of a beacon or tag (see Beacons and Tags above). The SDK is a piece of computer code that publishers include in their apps to enable ads to be shown and to enable related services, such as measurement or fraud prevention.

Cookie: A cookie is a small text file that is stored in a web browser by a website or ad server. By saving information in a cookie, websites and servers can remember preferences or recognize browsers from one visit to another or from one website to another. (See the Privacy Statement below and our Platform Cookie Policy for more information on how AppNexus uses cookies.) 

Non-Cookie Technology: Today’s online world is becoming increasingly complex, with a proliferation of new devices, software platforms, online services, and other technology. In this world, cookies are not always available. Therefore, companies are using alternative methods to distinguish devices. For example, some platforms, such as Apple’s iOS and Google’s Play Services for Android, provide unique IDs to be used for advertising. Most mobile devices are assigned unique identifiers that also may be used to distinguish devices. Additionally, it is possible to use mathematical techniques to make intelligent guesses about recognizing devices.

ID Synching: ID synching (sometimes also referred to as cookie syncing), though not often discussed, is a common and long-standing process in the industry. It enables advertisers to use data on multiple advertising platforms. Here’s an example of how it works. Let’s say you sell a product on your website, and a customer visits your site. You store a cookie to identify that customer’s browser with an ID of 12345 and associate that ID with information about what the customer shopped for on your site. If you want to use that information to advertise on other sites, you might buy the advertising through an online advertising marketplace. In order to buy the right ads, you’ll need to match ID 12345 to the ID the marketplace has assigned to the same customer (which let’s say for this example is ABCDE), you’ll have a record that says ID 12345 = Marketplace ID ABCDE. That way, when the marketplace offers to sell you an ad to be shown to ABCDE, your system will know that ABCDE is the same as 12345, and you can pick the right ad to show the customer.

Interest-Based Advertising: Interest-based advertising uses information collected across multiple web sites or mobile apps to predict users' preferences and to show ads that are most likely to be of interest to them. For example, if a user visits a travel site or uses a travel app, she might see travel-related ads on another site or app. Advertisers may also use other information they have or acquire about users’ interests. Users have choices with respect to this type of advertising, as discussed below. 

Precise Geographic Location: Your device, typically a mobile device, may be capable of sharing your precise geographic location with apps or web pages that you visit using that device. Devices use one or more methods to determine this location, including GPS coordinates and information about wifi networks in your vicinity. (Geographic location determined from IP address is typically not considered to be “precise.”) Devices such as iPhone or Android phones should require users’ consent before installing or using an app that accesses the device’s precise geographic location. The app, in turn, may make this information available to third party advertising companies in order to make the ads you see more relevant. 

Real-Time Transactions (Also called Real-Time Bidding or Programmatic Advertising): Advertising buyers are able to bid in “real time" for the opportunity to show an online advertisement when a web page is loaded or an app is used. The winning bidder gets to show its ad.

Of course, the explanations above are simplified. There are many resources available on the web to learn more about these concepts and online advertising in general. Although we have no responsibility for the content of these sites, we offer the following as good places to start learning:


AppNexus has created a technology platform (Platform or AppNexus Platform) that our clients use to buy, sell, and deliver online advertising, including interest-based advertising, mostly through real-time bidding. In other words, the AppNexus Platform does not itself buy, sell, or deliver ads, but provides technology that other companies use for those purposes.

The AppNexus Platform is designed to enable other companies (our clients) to buy, sell, or deliver advertising using “Platform Data” that clients may collect using the Platform, derive from their use of the Platform, or acquire from other sources and then use on the Platform. The Privacy Statement below describes how AppNexus handles Platform Data that is collected or used on the Platform by and on behalf of our clients.


For simplicity, accuracy, and clarity in discussing our privacy practices, we refer to the data collected and used on the Platform as “Platform Data.” Platform Data includes data elements such as information received from the web browser, operating system, or device, including such things as information about the browser type and browser settings, information about the operating system or device, the web address of a web page visited, the name or type of mobile app, the address of the referring web page, the IP address of the device, cookie information, and other information about a web page or app. Collectively, this data might be called HTTP header data or clickstream data. Platform Data also includes information about the geographic location of the device. It may also include inferences or information about users’ interests that are created, acquired, or used by our clients. Platform Data does not include, and AppNexus does not collect, use, or allow on the Platform, data that, by itself, directly identifies an individual, such as name, address, phone number, email address, or government identifier.


Although the specific cookies may change from time to time, this describes the purposes for which the AppNexus Platform employs cookies to operate, and enable clients to use, the Platform. For a detailed description of cookies set by the Platform, see AppNexus Cookies.

  • The Platform uses unique cookies to identify web browsers and to store data for advertising purposes, including interest-based advertising.
  • The Platform uses unique cookies to store ad delivery and reporting data for clients, such as, for example, which ad was shown, the number of times a particular ad has been shown, and how recently an ad has been shown to a particular web browser.
  • The Platform uses unique cookies to enable ad buyers to track users' responses (clicks and conversions) to ads purchased on the platform.
  • The Platform uses non-unique cookies for server load-balancing and similar technical purposes.
  • The Platform uses non-unique cookies to store users' opt-out choices.
  • The AppNexus Platform is designed to use only Platform Data, as described in this document, and AppNexus has contractual provisions that prohibit clients of the Platform from associating Platform cookies with data that, as explained above, by itself, directly identifies an individual.

Note that the Platform may also use some Non-Cookie Technologies (as defined above and as detailed below).


Effective February 24, 2015

This privacy statement describes AppNexus's practices and policies with regard to the Platform Data that is collected or used on the Platform by AppNexus Inc. on behalf of its clients.

What information do we collect and use?

The Platform is designed to collect and use only Platform Data as described in this document. Details.

How do we collect information?

The Platform uses cookies, beacons, tags, mobile SDKs, and some non-cookie technologies to collect and store Platform Data about web browsers and devices across web sites and apps and over time. Details.

For what purposes do we use the collected information?

AppNexus uses the information to provide, operate, manage, maintain, and enhance the Platform. Details.

What information do we share with third parties?

Clients have access to their Platform Data that is collected and used on the Platform. AppNexus may provide Platform Data to partners and service providers for the purpose of operating managing, maintaining, or enhancing AppNexus' services, or as required by law, AppNexus does not share the information collected on the Platform with others, unless legally required. Details.

How is the information stored and how long is it kept?

Platform Data is stored using generally accepted security standards. It is retained for up to 18 months from the date of collection, and is then aggregated. Details.

What are your choices?

Web browser users may opt out of use of the Platform for interest-based advertising in their web browser. Mobile app users have access to choices provided by certain apps or in their device system software. Details.

What happens if this privacy statement is changed?

Check this policy for changes. Material changes will not be applied to previously collected Platform Data. Details.


Send a message here.


  • The AppNexus Platform allows clients to collect and use Platform Data.
  • The Platform enables clients to use information provided by third-party sources. Clients and third parties use ID synching to enable the use of this information through the Platform.
  • AppNexus does not collect, use, or allow its clients to transfer to or use on the Platform, data that, by itself, directly identifies an individual, such as name, address, phone number, email address, or government identifier.


  • The Platform uses cookies, beacons, tags, mobile SDKs, and in some cases non-cookie technologies, to collect Platform Data associated with particular web browsers or devices.


  • AppNexus uses the information collected on the Platform to provide, operate, manage, maintain, and enhance the Platform.
  • The Platform enables AppNexus's clients to use their Platform Data to buy and sell online advertising, including interest-based advertising, using real-time transactions.
  • Particular advertising-related purposes for which AppNexus clients may use the Platform Data on the Platform include:
    • Interest-based advertising (To opt out of interest-based advertising on the Platform, go to the “What are your choices?" section below.)
    • Limiting the number of times a user sees a particular ad
    • Showing ads in a particular sequence
    • Customizing ads to a particular geographic region
    • Showing ads related to the content of the web page on which they are shown
    • Determining when users respond to ads
    • Reporting aggregated statistics regarding, for example, the effectiveness of online advertising campaigns

Typically, companies using a platform such as the AppNexus Platform own the data that they provide to and derive from the Platform. While the AppNexus Platform is designed to use only certain types of data, and Platform clients’ are prohibited from bringing data onto the Platform that directly identifies an individual, when clients remove their data from the Platform, their use of data is governed by their own privacy policies and applicable laws, rules, or regulations.


AppNexus may, to provide, operate, manage, maintain, and enhance AppNexus's services, provide Platform Data to partners and service providers. AppNexus may provide, or enable others to collect, information for purposes of detecting and preventing malicious activity or invalid traffic. In addition, AppNexus may disclose such information in the event we reasonably suspect malicious activity or invalid traffic, or believe that we are legally required to do so. AppNexus may also share aggregated data derived from the Platform, including, for example, statistics about Platform activity. Clients have access to their Platform Data that is collected and used on the Platform. Finally, we may transfer Platform Data to a successor entity in connection with a corporate merger, consolidation, sale of assets, bankruptcy, or other corporate change.


  • AppNexus uses generally accepted industry security standards on the Platform.
  • Platform Data is retained in the Platform in non-aggregated form for up to 18 months from the date of collection. Aggregated data is used for reporting and analysis, and may be stored in the Platform for up to 2 additional years.
  • When clients remove their data from the Platform, their storage and retention of data is governed by their own privacy policies and applicable laws, rules, or regulations.



You can opt out of interest-based advertising.

AppNexus Web Browser Opt Out: You can click below to opt out of having the Platform used to select ads for your browser based on your online web browsing behavior. When you opt out, an opt out cookie (from will be stored in your web browser. The Platform will know the choice you have made when it sees your opt out cookie, and will apply your choice to all companies’ use of the Platform. If you block or delete the opt out cookie, the Platform will not see your choice.

  • The opt out cookie may not work if your browser is configured to block third-party cookies.
  • If you delete your cookies, you will need to opt out again. There are browser plugins to help you preserve your opt out cookies. For more information, please visit
  • The opt out only applies to the browser in which you set it. For example, if you set the opt out while using Firefox, but then use Chrome, the opt out will not be active in Chrome. To opt out in Chrome, you will need to repeat the opt out process.
  • The opt out does not block or delete cookies, or prevent the use of cookies or other technologies for purposes other than selecting ads based on your interests as inferred by your online behavior. If you opt out, data may still be collected about your web browsing activities and you will still see advertising. Ads may be selected, for example, based on the content of the web page in which they are shown. If you wish to block or delete cookies altogether, you can use web browser settings to do so. 
  • To learn more about interest-based advertising, and to access the opt outs of other online advertising companies, visit the Network Advertising Initiative opt out page.

AppNexus Mobile App Opt Out: Mobile device system software such as Apple iOS or Google Play Services provide an opt out choice that will be communicated to companies providing in-app advertisements. For more information, or to opt out using these mechanisms, consult your device settings.


AppNexus supports industry self-regulation, and endorses best practices and self-regulatory requirements that apply to the Platform. AppNexus is a member in good standing of the Network Advertising Initiative (NAI), and adheres to the NAI Code of Conduct for Web. Additionally, the following industry sites provide useful information about industry self-regulation of interest-based advertising:


If we transfer personal information from the European Union to the United States, we adhere to the principles of the U.S.-E.U. Safe Harbor Framework and U.S.-Swiss Safe Harbor Framework, as set forth by the U.S. Department of Commerce ( For questions or complaints related to the collection, retention, or use of data under either of the Safe Harbor Frameworks, please contact us here. Unresolved privacy complaints under either of the Safe Harbors will be referred to the American Arbitration Association as an independent dispute resolution mechanism.


Check this policy for changes. We may change this privacy statement at any time. However, if we were to make material changes, those changes would not be applied to Platform Data collected prior to such changes.


If you have questions about privacy on the AppNexus Platform, you may send us a message here.