There was an unexpected error authorizing you. Please try again.

Demystifying Identifiers and Understanding Their Critical Roles in Advertising

By Dennis Buchheim and Amit Shetty

“Identity” is a term that gets used a lot in digital advertising, usually in the context of identifying and targeting consumers. At the IAB Tech Lab, we look at identity in a broader context, covering consumers, creative assets, and the businesses involved in the supply chain. Understanding each of these identities is driven by a variety of objectives that we will cover later, but in all cases, the end goal is to enable systems in the advertising supply chain to recognize entities and enable a number of processes to operate effectively. The corresponding identifiers are the core building blocks that help fight fraud, improve brand safety, deliver a better experience to consumers, and support measurement and attribution.

In this post we will go through the various identifiers in the ecosystem, their importance, and the initiatives supported by IAB Tech Lab and others around these identifiers.

What’s in a Name?

An identifier is a means of consistently recognizing a specific entity as distinct from others across multiple interactions.  In database terms, it is a “key” that enables the lookup of an entity.  In general, we want identifiers that are machine-readable, are unlikely to collide with each other, and are consistently available. An “identity”, on the other hand, is more than just name recognition. It is considered to be an approximation of the entity; a collection of metadata describing the entity, that enables platforms to perform various business transactions (interests, measurement, rights, etc.) related to that entity.

There are three categories of identifiers, mapping on to the three entities that we are interested in – consumers, (advertising) assets, or businesses in the digital advertising supply chain.

  1. Consumer IDs – These attempt to identify individual users or a group of people within a household (all generally anonymously), but may ultimately be tied to devices or browsers, depending on the available data (such as logins) on various platforms. Examples are cookies, DeviceIDs or IFAs (Identifier For Advertising) on mobile/OTT (Over-The-Top video) devices.
  1. Asset IDs – These identify creative assets as they go through the advertising supply chain. Examples are asset IDs such as Ad-ID for ad creatives or EIDR (Entertainment Identifier Registry) for publishers’ video program content assets.
  2. Business IDs – These identify the various companies involved in the advertising supply chain. Examples include TAG (Trustworthy Accountability Group) and ads.txt (Authorized Digital Sellers).

Usage & Current Challenges

1. Consumer IDs – These are associated with individuals or households – ideally without personally identifiable information (PII) – for the purpose of understanding user behaviors and interests for targeting and personalization, assessing where/when a person saw an ad (for measurement and attribution), and applying known privacy preferences consistently across sites, apps, and devices. This allows platforms to develop insights into users’ needs and deliver a better experience by providing more relevant ads.

  1. Examples: Usernames / email addresses / cookies / IDFA (Apple’s Identifier For Advertising) / RIDA (Roku’s Identifier for Advertising)
  2. Challenges:
    1. Ensuring privacy: Even if a user opts out of interest-based tracking, there are use cases such as frequency capping that are important to the user experience, and may require a temporary/ephemeral/synthetic ID. Also, many IDs (email, cookies, etc.) inherently include PII data and so data must be processed and anonymized before being used.
    2. Avoiding data loss, too many trackers: Maintaining identity across different publishers or platforms is a challenge. The use of multiple cookies results in bad user experience and can easily result in data loss.
    3. Lack of transparency and standardization: Most third-party identity solutions rely on proprietary techniques to associate devices with individuals and households, resulting in a lack of transparency into the rigor of these processes; inconsistencies in validation metrics including coverage/match rate, precision/accuracy, and recall; and little consensus on how best to evaluate and differentiate solutions against different marketing objectives.
    4. Identity across multiple devices: Ideally companies would like to identify users across multiple devices (cell phones, laptops, OTT devices), in order to deliver better targeting and measurement. These “device graphs” are difficult to build and may be limited when devices are shared within a household or office.
  3. IAB Tech Lab initiatives:
    1. DigiTrust ( is a neutral, non-profit, industry-wide collaboration of ad tech platforms and premium publishers utilizing a standardized user token in order to improve the consumer online experience. DigiTrust was acquired by IAB Tech Lab in April 2018, and now operates as a service from IAB Tech Lab. The DigiTrust service and technology solution creates a randomly-generated, encrypted user token, which is propagated by and between its members in lieu of billions of proprietary pixels and trackers on web pages daily. The DigiTrust ID Working Group is working on the roadmap for this initiative
    2. The OTT Technical Working Group is working to standardize an IFA (Identifier For Advertising) for OTT (Over-The-Top TV) devices. We expect this will significantly increase OTT ad market share by improving the addressability and measurement of corresponding inventory, and by allowing buyers to treat it similarly to other platforms/channels.
    3. The Identity Standards & Services and Data Transparency Working Groups are defining key processes used for (a) sourcing data for user-level device graphs, (b) developing confidence in associations among devices, (c) validating third-party solutions around a standardized set of quality or accuracy metrics, and (d) defining best practices for ensuring privacy compliance and communication of user consent across devices.

2. Asset IDs – These are associated with program content and advertising creatives, to make it easier to understand what was or will be shown to a consumer, ensuring that the right content is delivered to the right individual (separating ads from competitors, age appropriate etc.), and enabling accurate measurement/tracking of which creatives were displayed where and who they were presented to. Asset IDs are also important to help with brand safety by tying the ID to metadata about the creatives.

  1. Examples:– Ad-ID and EIDR. These are independent asset identity management systems that can be used across all publishers. In addition, publishers may maintain proprietary asset IDs, which at a minimum will help analysis within their platforms.
  2. Challenges:
    1. Lack of adoption of standard identifiers: The industry has not fully embraced the use of standard asset identifiers, and the use of standardized metadata.
    2. Ensuring the ID is consistently and correctly passed along as the asset moves through the supply chain (for example, ID stored in a file’s metadata -> passed in a VAST tag -> fired in a tracking beacon -> logged into a reporting database).
    3. Establishing different asset IDs when making minor content changes to creatives to support various platforms: Facebook vs. Snap or mobile vs. OTT vs. broadcast.
  3. IAB Tech Lab initiatives:
    1. The Digital Video Working Group has added the concept of a “Universal AdID” node in VAST4, which allows all video creatives to be associated with an identifier, such as Ad-ID in the United States or Clock ID in the UK.
    2. We are working with a group of industry organizations as a part of the TV Convergence Task Force to embed metadata such as asset IDs into video creatives.
    3. Our Taxonomy Working Group is working on Ad Product taxonomy and recently updated our Content Taxonomy. This taxonomy combined with the asset IDs helps with brand safety and personalization.
    4. IAB Tech Lab is working with Ad-ID to define and standardize use cases where the use of a creative ID helps streamline video ad delivery.

3. Business IDs – These identify the trusted or known publishers, advertisers, and vendors that provide content and ads to consumers, and execute a range of other functions across the supply chain. These IDs are used mainly to manage trust, reduce fraud, and improve transparency.

  1. Certification solutions:
    1. TAG-ID – The TAG (Trustworthy Accountability Group) Registry is a protected system of advertising supply chain participants that demonstrate their commitment to higher standards of transparency and disclosure to their partners. TAG-ID is a unique, global, and persistent identifier that enables one business to identify its partners across the supply chain.
    2. JICWEBS in the UK certifies processes with transparency and trust in mind.
  2. Entity validation solutions:
    1. ads.txt (Authorized Digital Sellers) – While not a typical identity system, this initiative has significantly helped clean up the ad ecosystem by allowing publishers to identify their authorized resellers. This optionally also includes the resellers’ TAG-IDs.
    2. ads.cert – Also not a typical identity solution, this will be a public/private key system used to identify publishers making a bid request. Ads.cert will be released as part of OpenRTB 3.0 (Real-Time Bidding).

What Can I Do?

  1. Understand the various IDs described and determine which ones are critical to your organization.
  2. Get TAG certified and get a TAG-ID that you can use with your partners. IAB in the U.S. is starting to require IAB members to register with TAG in an effort to reduce fraud and problematic ads and content.
  3. Bind your creative assets to Ad-IDs & EIDRs and ensure that they get tracked across the ad delivery supply chain.
  4. Understand and follow best practices around consumer privacy and data quality.
  5. Engage with us on identity initiatives:
    1. Join IAB Tech Lab working groups such as the Identity Standards Working Group or the OTT Technical working group to help define standardized identity offerings.
    2. Consider joining our recently formed Blockchain Working Group, which is looking into identity and trust-related solutions for the advertising supply chain.






Dennis Buchheim
SVP & General Manager, IAB Tech Lab

Amit Shetty
Senior Product Director, Video & Audio