
2024 marked a significant year. AI became integral to our workflows, commerce and retail media networks soared, and Google did not deprecate cookies. Amidst these changes, ID bridging emerged as a hot topic, raising questions around identity reliability and transparency, which necessitated industry-wide standards. We believe the latest IAB OpenRTB specifications, produced in conjunction with supply and demand-side partners, set up the advertising industry for more transparent and effective practices.
So, what exactly is ID bridging?
As signals, like third-party cookies, fade, ID bridging emerged as a way for the supply-side to offer addressability to the demand-side. ID bridging is the supply-side practice of connecting the dots between available signals, that were generated in a way that is not the expected default behavior, to understand a user’s identity and communicate it to prospective buyers. It enables the supply-side to extend user identification beyond the scope of one browser or device.

Imagine you visit a popular sports website on your laptop using Chrome. Later, you use the same device to visit the same sports website, but this time, on Safari. By using identity resolution tools, a supply-side partner can infer that both visits are likely from the same user and communicate with them as such.
ID bridging is not inherently a bad thing. However, the practice has sparked debate, as buyers want full transparency into the use of a deterministic identifier versus an inferred one. This complicates measurement and frequency capping for the demand-side. Before OpenRTB 2.6, ID bridging led to misattribution as the demand-side could not attribute ad exposures, which had been served to a bridged ID, to a conversion, which had an ID different from the ad exposure.
OpenRTB 2.6 sets us up for a more transparent future
In 2010, the IAB, along with supply and demand-side partners, formed a consortium known as the Real-Time Bidding Project for companies interested in an open protocol for the automated trading of digital media. The OpenRTB specifications they produced became that protocol, adapting with the evolution of the industry.
The latest evolution, OpenRTB 2.6, sets out standards that strive to ensure transparency in real-time bidding, mandating how the supply-side should use certain fields to more transparently provide data when inferring users’ identities.
What’s new in OpenRTB 2.6?
Here are the technical specifications for the industry to be more transparent when inferring users’ identities:
- Primary ID field: This existing field now can only contain the “buyeruid,” an identifier mutually recognized and agreed upon by both buyer and seller for a given environment. For web environments, the default is a cookie ID, while for app activity, it is a mobile advertising ID (MAID), passed directly from an application downloaded on a device. This approach ensures demand-side partners understand the ID’s source.
- Enhanced identifier (EID) field: The EID field, designated for alternative IDs, now accommodates all other IDs. The EID field now has additional parameters that provide buyers transparency into how the ID was created and sourced, which you can see in the visual below:

Using the above framework, a publisher who wants to send a cross-environment identifier that likely belongs to the same user would declare the ID as “mm=5,” while listing the potential third-party identity resolution partner under the “matcher” field, which the visual below depicts. This additional metadata gives the demand-side the insights they need to evaluate the reliability of each ID.

“These updates to OpenRTB add essential clarity about where user and device IDs come from, helping buyers see exactly how an ID was created and who put it into the bidstream. It’s a big step toward greater transparency and trust in the ecosystem. We’re excited to see companies already adopting these updates and can’t wait to see the industry fully embrace them by 2025.”
Hillary Slattery, Sr. Director, Programmatic, Product Management, IAB Tech Lab
Experian will continue supporting transparency
As authenticated signals decrease due to cookie deprecation and other consumer privacy measures, we will continue to see a rise in inferred identifiers. Experian’s industry-leading Digital Graph has long supported both authenticated and inferred identifiers, providing the ecosystem with connections that are accurate, scalable, and addressable. Experian will continue to support the industry with its identity resolution products and is supportive of the IAB’s efforts to bring transparency to the industry around the usage of identity signals.
Supply and demand-side benefits of adopting the new parameters in OpenRTB 2.6
- Partner collaboration: Clarity between what can be in the Primary ID field versus the EID field provides clear standards and transparency between buyers and sellers.
- Identity resolution: The supply side has an industry-approved way to bring in inferred IDs while the demand side can evaluate these IDs, expanding addressability.
- Reducing risk: With accurate metadata available in the EID field, demand-side partners can evaluate who is doing the match and make informed decisions on whether they want to act on that ID.
Next steps for the supply and demand-sides to consider
For supply-side and demand-side partners looking to utilize OpenRTB 2.6 to its full potential, here are some recommended steps:
For the supply-side:
- Follow IAB Specs and provide feedback: Ensure you understand and are following transparent practices. Ask questions on how to correctly implement the specifications.
- Vet identity partners: Choose partners who deliver the most trusted and accurate identifiers in the market.
- Be proactive: Have conversations with your partners to discuss how you plan to follow the latest specs, which identity partners you work with, and explain how you plan to provide additional signals to help buyers make better decisions.
We are beginning to see SSPs adopt this new protocol, including Sonobi and Yieldmo.
“The OpenRTB 2.6 specifications are a critical step forward in ensuring transparency and trust in programmatic advertising. By aligning with these standards, we empower our partners with the tools needed to navigate a cookieless future and drive measurable results.”
Michael Connolly, CEO, Sonobi
These additions to the OpenRTB protocol further imbue bidding transactions with transparency which will foster greater trust between partners. Moreover, the data now available is not only actionable, but auditable should a problem arise. Buyers can choose, or not, to trust an identifier based on the inserter, the provider and the method used to derive the ID. While debates within the IAB Tech Lab were spirited at times, they ultimately drove a collaborative process that shaped a solution designed to work effectively across the ecosystem.”
Mark McEachran, SVP of Product Management, Yieldmo
For the demand side:
- Evaluation: Use the EID metadata to assess all the IDs in the EID field, looking closely at the identity vendors’ reliability. Select partners who meet high standards of data clarity and accuracy.
- Collaboration: Establish open communication with supply-side partners and tech partners to ensure they follow the best practices in line with OpenRTB 2.6 guidelines and that there’s a shared understanding of the mutually agreed upon identifiers.
- Provide feedback: As OpenRTB 2.6 adoption grows, consistent feedback from demand-side partners will help the IAB refine these standards.
Moving forward with reliable data and data transparency
As the AdTech industry moves toward a cookieless reality, OpenRTB 2.6 signifies a substantial step toward a sustainable, transparent programmatic ecosystem. With proactive adoption by supply- and demand-side partners, the future of programmatic advertising will be driven by trust and transparency.
Experian, our partners, and our clients know the benefits of our Digital Graph and its support of both authenticated and inferred signals. We believe that if the supply-side abides by the OpenRTB 2.6 specifications and the demand-side uses and analyzes this data, the programmatic exchange will operate more fairly and deliver more reach.
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Industry leaders recently gathered at the influential Beet Retreat 2023 conference held in Santa Monica, sharing forward-looking perspectives on the future of advertising. This renowned event known for its diverse mix of leaders from TV, agencies, advertising, and technology sectors, was enriched by insights from Experian’s very own Chris Feo, SVP of Sales & Partnerships, and Kimberly Gilberti, Chief Product Officer. Both Feo and Gilberti brought their expertise and perspectives for harnessing the potential of high-growth connected TV (CTV) advertising. The era of connected everything at Beet Retreat 2023 In the “Era of Connected Everything,” panel, Feo dived into the concept of a ‘connected everything’ world. He emphasized the importance of balancing consumer and privacy expectations with the increasing integration of AI and machine learning. “As decisioning evolves, creative tech and data derived from creative scale will play a bigger role.”chris feo, svp, sales & partnerships Feo further discussed the potential of creative technology, particularly in how AI and machine learning could revolutionize content personalization. He cited examples where the same creative content is used indiscriminately across diverse demographics, suggesting a future where creative content adapts and performs well for a variety of audience identities. Experian's balanced approach at Beet Retreat 2023 During a fireside chat, Gilberti shared her vision on the transformative role of television in the advertising technology landscape. “Connecting exposure to business outcomes is the holy grail of measuring CTV and effectiveness.”kimberly gilberti, chief product officer Her insights reflected the growing interplay between digital and traditional TV advertising, and the opportunities arising from this convergence. Gilberti emphasized the critical role of data analytics in enabling advertisers to tailor content more effectively to diverse TV audiences. She envisioned a future where the integration of digital strategies and traditional TV advertising create a more cohesive and impactful AdTech approach. Future focus: Diversification and partnerships Both Feo and Gilberti underscored the need for advertisers to diversify their partnerships. By working with a variety of partners, you can mitigate risks and foster innovation, ensuring you are not overly dependent on a single channel or approach. Navigate what’s next with Experian Experian's contributions at Beat Retreat 2023 underscore our pivotal role in the AdTech industry. With a unique balance of offline and online data expertise, we are not just adapting to changes but leading the way in innovation and strategy. Our insights and approaches, as highlighted by Feo and Gilberti, demonstrate our commitment to guiding the industry through its rapid evolution, making our role indispensable in the future of advertising technology. At Experian, we’re your partner in data-driven marketing and can help make your interactions more meaningful. To learn more, connect with a member of our team today. Connect with us Latest posts

Experian is excited to introduce our new Geo-Indexed audiences. Our Geo-Indexed audiences use a new advanced indexing classification technology to identify and reach consumers based on their geo-regional attributes. These audiences can help you discover, segment, and craft messaging for consumers without the use of sensitive personal information, so you can confidently reach your target audience without sacrificing data privacy. In this blog post, we’ll review how our new Geo-Indexed audiences can help you reach your audience while balancing data privacy and accuracy. How we collect and use data is changing The AdTech industry is undergoing a transformation as various forces shape its trajectory. One significant factor is legislation, with as many as 26 states currently considering data privacy laws. Consumer preferences also play a crucial role, as more individuals look to brands for responsible and ethical data handling practices. According to Forbes, 82% of people view brands positively when they consciously opt to refrain from using personal data for personalized ads. Major players in the field such as Apple and Google are actively pushing for a shift away from traditional methods like cookies and other identifiers in data collection and usage. These developments mark a considerable shift in how we use data. Many brands are seeking a few solutions to continue to find and reach their target audience online, but at Experian, we see a great opportunity for innovation and impact within geo-based targeting solutions. “We predict that over the next year, you will begin to see innovations in geo-based targeting methodologies that satisfy the industry's need for audience targeting with responsible data strategies. By embracing innovations in geo-based targeting and adhering to responsible data strategies, you can not only comply with these laws but continue to reach your intended audiences effectively.”jeremy meade, vp, marketing data & operations Introducing Experian’s Geo-Indexed audiences Geo-Indexed audiences from Experian allow brands to reach consumers and households based on geographic regions that over-index for a common set of attributes. Our Geo-Indexed audiences give brands the ability to: Stay connected: Maintain a touchpoint with consumers as other audience targeting solutions disappear or reduce scale due to new legislation. Expand your audience reach: With our sophisticated geo-indexing methodology, you will be reaching your target audience’s circle of influence within the geo-region. Execute where you want: By linking our Geo-Indexed audiences to Experian’s persistent identifiers, you can activate these audiences on the shelf of your platform of choice. As a part of the release of Geo-Indexed audiences, we will be rolling out three main categories: Language Ethnic Group Demographics which include: Education Household Income Marital Status Occupation Presence of Children Over the next year, we will continue to release new audiences within Geo-Indexed audiences. How you can use Geo-Indexed audiences An Auto brand has a new corporate policy restricting the use of sensitive personal information in audience targeting but would like to reach high-income earners. To reach their target audience they use the Geo-Indexed audiences to reach households who are in geographic regions that index highly for income ranges ‘$175,000 – $199,999’ and ‘$200,000+.’ Prioritize privacy without sacrificing accuracy with Experian’s Geo-Indexed audiences Our Geo-Indexed audiences are available in most major data and demand-side platforms. Visit our partner page for more information. Don’t see our audiences on your platform of choice? We can help you build and activate an Experian audience on the platform of your choice. Connect with our audience team Latest posts

In this article… What is a walled garden? Integrated marketing is more important than ever Perspectives on walled gardens from Cannes Lions 2023 Walled gardens aren’t going away in the near future The fuure of walled gardens Digital marketers face an ongoing challenge in the form of "walled gardens," closed online ecosystems where it is difficult to access user data. As we get ready for 2024, it's more important than ever for marketers to evaluate the current challenges and opportunities surrounding walled gardens and to take stock of the impact of walled gardens in marketing as an industry. What is a walled garden? A walled garden is a closed online ecosystem controlled entirely by one tech company. Advertising on these ecosystems is fairly locked down, as major tech companies with walled gardens tend to tightly control access to the user data, content, and advertising that appears within the ecosystems. Some examples of walled garden ecosystems include Google, Facebook, Amazon, and Apple. These walled gardens have particular advantages, like access to massive user bases and precise targeting within the individual ecosystems. It can also be difficult to reach said audiences outside of the ecosystems, reducing the amount of control you have over your advertising strategies. Learn more about walled gardens. Learn the differences between walled gardens and hedged gardens. Integrated marketing is more important than ever Today, it's become more crucial to connect with consumers over multiple touchpoints, which can be done from tech like connected TV (CTV) to websites, mobile devices, and even shopping in a physical store. However, as integrated marketing gains utility, many platforms with walled garden ecosystems have increased, making a truly integrated and personalized marketing strategy more difficult in many situations. As a result, many marketers have realized the value of a more streamlined marketing approach, emphasizing the importance of fully integrated advertising strategies. Though there are surely marketing advantages to gain from walled garden ecosystems, especially in audience size, the challenges they pose will require you to innovate and find more creative ways to engage with your audience from platform to platform. Perspectives on walled gardens from Cannes Lions 2023 Offering a poignant view of industry trends and ideas, the Cannes Lions International Festival of Creativity of 2023 had much to say about the significance of walled gardens in the marketing world. Let's look at two key takeaways from this year's festival. Retail media In recent years, many retail companies have started selling ad space within their own walled garden shopping platforms, dubbed "retail media." Platforms like Amazon and Walmart have developed their own particular advertising ecosystems where they sell ads to marketers within the shopping environment itself. Navigating the sell-side of retail media’s walled gardens While retail media offers marketers unique opportunities, it's not without its challenges. For one, ad space in these environments is limited, so the competition can be difficult on the sell-side, leading to higher ad costs. Additionally, this shift in dynamic also forces marketers to change how they prioritize their marketing channels, looking closer at the results of their efforts rather than focusing on particular channels within the platforms themselves. Opportunities in the buy-side of retail media’s walled gardens Brands on the buy-side see various benefits from advertising within retail media channels and walled gardens. By browsing in an online shopping environment, the users in these ecosystems are likely high-intent shoppers, people who are further down the sales funnel and who are ready to make a purchase soon. Shoppers can also be precisely targeted within these environments, as marketers are given the ability to access very specific audience segments based on details like shopping behavior, preferences, and even purchase history. Omnichannel marketing To more effectively engage audiences even among an abundance of walled garden ecosystems, speakers at the 2023 Cannes Lions Festival discussed the importance of omnichannel marketing. By emphasizing strategies that reach the consumer through multiple touchpoints, marketers can deliver a unified brand experience across channels. This allows marketers to focus more on results than specific advertising channels, including walled garden platforms. Walled gardens aren’t going away in the near future Though various challenges are associated with walled gardens in advertising, they aren't going anywhere. So, what's the current state of these environments throughout the industry? Efforts are being made to break down walled gardens in tech In a handful of countries, regulatory actions have been put forward to address how dominant many major tech companies are in their respective markets. One major example of this is Meta and Google's entanglements in Canada. Currently, neither company can display news on their websites in the Canadian market. This decision was reached to give Canadian news agencies more control over their advertising revenue since, previously, the tech giants received more views and, therefore, gained the ad revenue. Though relatively small, this does indicate a certain shift in dynamic. Why companies are resisting Despite their challenges, walled gardens in 2023 persisted, mainly because they are particularly adept at generating revenue for the tech companies that control them. In 2022, 78 percent of global digital advertising revenue came from these closed ecosystems, and projections expect that figure to rise to 83 percent by 2027. From the viewpoint of a company that operates in a walled garden, the idea of releasing their control over their environment represents losing out on a stream of vast revenue, making letting go of a walled garden ecosystem an unattractive prospect. The future of walled gardens As time progresses, what can digital marketers like you expect from walled garden ecosystems in the near future? A cookieless future A huge element to consider is the transition to a cookieless future. Many major browsers have begun phasing out the use of third-party cookies. In the wake of this decision, many are looking for reasonable alternatives that allow for behavior tracking and more personalized advertising experiences. Solutions like Experian's identity resolution can provide a strong alternative option, allowing marketing strategies to adapt to the current landscape. An influx of mini gardens You should also anticipate the proliferation of various smaller, specialized walled garden ecosystems in the future. These so-called "mini gardens" specialize in more niche audiences and industries, and they can present their own challenges and opportunities. Alternative IDs As you search for new identification methods outside cookies, various alternatives have presented themselves, requiring further exploration and experimentation. Among these are privacy-compliant solutions like Unified ID 2.0, which allow you to serve more personalized ads without compromising the consumer's privacy. Navigating the evolving landscape of walled gardens in 2024 As we begin 2024, you will continue facing opportunities and challenges regarding walled gardens. The 2023 Cannes Lions International Festival of Creativity re-emphasized how important it is for marketers to stress omnichannel marketing within walled garden environments and become well acquainted with identity resolution solutions as we move into a cookie-less future. All of this requires you to become comfortable with walled gardens being here to stay and innovate to navigate an evolving and developing landscape. We’re here to help you navigate the evolving landscape of walled gardens in 2024. Contact us today. Get in touch Latest posts