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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In the ever-evolving and soon-to-be cookieless advertising world, brands and agencies need help finding and maintaining access to accurate and comprehensive marketing data that enables them to reach the audience segments that matter most. Flashtalking by Mediaocean and Experian have a collaboration in place to do just that. Through this partnership, Experian’s more than 2,400 syndicated audiences are available for activation within the Flashtalking platform and its Social Ads Manager. “There are a lot of audience segments and data disappearing within the advertising industry right now because of the deprecation of third-party cookies, but Experian’s syndicated audiences are built for this new privacy-first world. Through this partnership, Flashtalking's clients gain access to some of the industry's most actionable on-the-shelf and custom audience capabilities for activation and targeting across the publishers and social platforms that matter most. It’s as easy as identifying the segments that matter to your brand and activating them everywhere they exist with a few simple clicks.” – Ben Kartzman, COO, Flashtalking by Mediaocean This partnership unites the power of Flashtalking's best-in-class independent omnichannel advertising platform with Experian’s comprehensive audience intelligence, which spans 126 million households and 250 million consumers. “For the same reason that brands are investing more deeply in first-party data in the wake of third-party cookie deprecation, having access to the right audience segments has never been more important. Mediaocean offers access to the only independent ad server that’s powering truly omnichannel, personalized experiences, and we’re thrilled to be amplifying their ability to do that through Experian’s expansive audience segments.” – Colleen Dawe, Director, Sell-Side Sales, Experian The Flashtalking Social Ads Manager has long-standing relationships and technical integrations with all major platforms, including Facebook, Google Demand Gen, Instagram, LinkedIn, Pinterest, Snap, TikTok, and a forthcoming integration with Reddit. Experian data can be deployed through custom and syndicated segments within these platforms, providing clients with both reach and precision. The power of the Experian – Flashtalking collaboration Benefits to marketing organizations that tap Experian data and audience segments via the Flashtalking platform include the following: A unified customer view: Marketers can use Experian's comprehensive data within Flashtalking to create a unified view of the customer across multiple channels. This helps craft cohesive marketing strategies that deliver consistent messages, enhancing customer experiences and brand perception. Enhanced targeting and personalization: Marketers can access Experian's detailed audience segmentation and insights within Flashtalking to target campaigns effectively. They can personalize messages at scale based on demographic, psychographic, and behavioral data to increase engagement and conversion rates across all channels. Optimized cross-channel strategies: With Flashtalking's cross-channel capabilities, marketers can integrate Experian's insights to understand how different segments interact with various channels. This enables the design of optimized cross-channel strategies that cater to the preferences and behaviors of different audiences. Data-driven decision-making: This partnership combines Experian's in-depth consumer insights with Flashtalking's analytics and reporting tools to help marketers make informed decisions. This data-driven approach can improve campaign performance, optimize media spend, and reveal untapped market opportunities. Local market activation: Marketers can also use Experian's geographic and location-based data within Flashtalking to tailor campaigns to local markets. This localized approach can enhance relevance and response rates, providing a competitive edge in regional marketing efforts. Improved media efficiency: This collaboration also enables organizations to harness the power of Experian's data within Flashtalking to improve media planning and buying. They can identify the most effective channels and timeframes for reaching specific audiences, leading to more efficient and cost-effective media investments. Why choose Experian in Flashtalking For over 50 years, we have been a trusted single-source provider of data management solutions. Our expertise in offline and digital identity has enabled us to curate data from over 200 direct and active sources, offering a comprehensive view of consumers with granularity, accuracy and scale. Using this data, we can craft our syndicated audiences to cover many verticals and specialty categories. For example, a Flashtalking client in the automotive industry can supercharge its campaign efforts. Experian has found that automotive advertisers build segmentation using four major data categories: Automotive Demographics Lifestyles and Interests Retail Shoppers: Purchase-Based Directly within the Flashtalking platform, multiple syndicated audiences from Experian in each major data category specific to automotive are available that brands and agencies can activate on-the-shelf to reach consumers with targeted messaging and retargeting. Experian and Flashtalking are future-proofing advertising Together, Flashtalking and Experian will ensure advertisers can continue to deliver personalized, relevant, and impactful messages and experiences to consumers despite ongoing shifts within the data-driven marketing landscape, including the deprecation of third-party cookies in Chrome. This partnership offers greater access to audience segments built on privacy-safe insights with expansive reach, scale, and flexibility. Connect with us to learn more about how you can access Experian’s syndicated audiences through Flashtalking by Mediaocean. Contact us today About Flashtalking by Mediaocean Flashtalking unleashes the power of creative to make media work better. As the leading independent platform for personalization and intelligence across all marketing channels, our Creative Ad Tech bridges the gap between creative and media. We provide AI and automation to connect the silos between teams and deliver more efficient production, versioning, and distribution of creative. Our solutions operate at scale across CTV, Video, Display, Social, Native, Audio, DOOH, and Retail Media channels. As part of Mediaocean, Flashtalking is tied into the industry’s core ad infrastructure for omnichannel planning, buying, and billing. Visit flashtalking.com to learn more. Latest posts
Shoptalk 2024, the premier event for retail and e-commerce professionals, brought together industry leaders to discuss the latest trends and innovations shaping the future of retail. As the retail landscape continues to evolve, here are four key takeaways from Shoptalk 2024: 1. The continuing rise of retail media networks The evolution of retail media is propelling us into a new era of advertising and first-party data monetization. Retailers are using their valuable first-party data to offer targeted advertising opportunities on both their owned and operated channels — from sponsored content to personalized ads — and through offsite programmatic ads. However, the full potential of retail media networks (RMNs) is hindered by challenges in understanding and targeting shoppers beyond retail data, reaching customers across channels and validating measurement. To unlock the true value of RMNs, and turn these challenges into opportunities, companies should focus on four areas: Gain insights: Learn more about your customers and the customers your marketing partners care about. Create audiences: Use enriched data to build addressable audience segments for advertisers to target. Maximize reach: Expand your addressability and monetize your data on and off platform. Demonstrate success: Validate marketing impact by connecting ad exposures to outcomes. “It was evident at Shoptalk 2024 that the rise of retail media is unstoppable. The conversations, collaborations, and insights shared at the event cemented the position of retail media networks as the driving force behind the future of commerce.”Alison Hofelich, Sr. Account Executive, Big Box Retail & Grocery 2. Content-led commerce Content is becoming increasingly pivotal in driving commerce, with retailers investing in shoppable video to stimulate conversations and foster customer engagement. While video may not always lead to immediate transactions, it can start dialogues, offering retailers a platform to enhance customer loyalty and influence future sales. Retailers talked about their focus on connecting with Gen Z on a deeper level. PacSun highlighted initiatives like the launch of a gender-fluid line and continuous engagement with young consumers via social media for feedback. Additionally, PacSun talked about embracing "conscious capitalism" by co-creating with influencers and customers, recognizing the growing consumer preference for brands that make a positive impact. By collaborating with influencers and using user-generated content, retailers can create authentic experiences that resonate with their customers. 3. Data privacy and trust With data playing a central role in retail strategies, ensuring data privacy, and building trust with consumers are imperative. Retailers must prioritize transparency and security to safeguard customer information and nurture long-term relationships. While the focus may currently be on capturing Gen Z market share, businesses need to anticipate shifts in consumer demographics and adapt their strategies accordingly. Using customer data in a privacy-compliant way enables retailers to implement effective personalization strategies that drive long-term engagement and loyalty. “Retail media networks were at the center of Shoptalk 2024. In addition to retail media networks, the seamless integration of data to enhance customer personalization and the rising importance of targeting Gen Z were recurring themes."Kai Rood, Account Executive, Retail Apparel 4. The time to embrace AI is now Technology continues to drive innovation in retail, with advancements in AI reshaping the shopping experience. From virtual try-ons to personalized product recommendations, retailers are using AI to engage consumers and enhance product discovery. Testing and learning are essential for AI implementation, as companies navigate the risks and rewards of technological innovation. Navigate the future of retail with Experian Shoptalk 2024 provided invaluable insights into the future of retail, highlighting the importance of retail media networks, content-led commerce, data privacy, and tech innovation. By embracing these trends and innovations, retailers can position themselves for success in an ever-evolving marketplace. At Experian, our solutions are tailored to empower businesses in navigating this dynamic landscape. Through our Consumer Sync solutions, we bridge the gap between online and in-store touchpoints, ensuring a unified strategy for reaching audiences across channels and evaluating campaign performance. Our Consumer View solutions enable you to tap into 5,000 demographic and behavioral attributes to fill in any gaps on your customer. Go beyond category buyers by combining your first-party data and Experian's top ranked data to build custom audiences that lead to higher ROI for your advertisers. Connect with a member of our team today to get started. Latest posts
The marketing world has been preparing for years for the end of third-party cookies, and the news has shifted again. In 2025, Google paused its plan to phase out third-party cookies in Chrome, opting instead to introduce new privacy controls that let users manage how their data is shared. Even with this change, one truth remains: privacy-first; identity-driven marketing is no longer optional. For marketers, it’s about moving beyond reliance on cookies toward durable strategies built on trust, consent, and connected data. What is cookie deprecation? Cookie deprecation refers to browsers ending support for third-party cookies, which have long allowed advertisers to track user activity across multiple websites. These cookies were the foundation of behavioral targeting and attribution. By contrast, first-party cookies, created by a brand’s own website, will continue to function. They store essential information like logins or preferences and are central to modern data collection strategies. The change aims to improve privacy and transparency, giving users more control over their information. For marketers, it represents a shift from broad tracking to consented, identity-based engagement. Experian’s view: While third-party cookies may linger longer than expected, identity should remain the cornerstone of every marketing strategy. Why is cookie deprecation reshaping the industry? The shift toward privacy-first marketing didn’t begin with Google, but Chrome’s decision to limit third-party cookies has amplified the impact. Safari and Firefox removed third-party tracking years ago, but Chrome’s dominance, with roughly 65 percent of the global browser market, makes its shift a defining moment for advertisers. Apple App Tracking Transparency (ATT): Requires user permission before app tracking. Global Privacy Control (GPC): Lets users signal how their data can be shared. General Data Protection Regulation (GDPR) and California Consumer Privacy Act (CCPA): Enforce consent and transparency in data use. Google Tracking Protection: Now limits cross-site tracking for 1 percent of Chrome users, about 30 million people, before a full rollout. The platform response Google’s Privacy Sandbox initiative and new user privacy control interface aim to balance personalization with user protection. These updates mark a shift toward data transparency rather than full deprecation. Experian supports this evolution by helping marketers adapt through privacy-led identity, data collaboration, and measurement solutions that meet compliance standards while maintaining addressability and performance across channels. How will cookie deprecation affect marketers? Marketers will notice several shifts: Less cross-site visibility: Without third-party cookies, connecting behavior across websites becomes difficult, making it harder to attribute conversions. Greater dependence on first-party data: Data collected directly from consumers (emails, preferences, purchase history) will be crucial for targeting and measurement. Increased adoption of alternative IDs: Solutions like Experian’s alternative IDs help maintain addressability and measurement in a cookieless world. Renewed focus on contextual advertising: Relevance now depends on where an ad appears rather than who sees it. New compliance expectations: Marketers must prove transparency and respect for consent under tightening global privacy laws. What challenges should marketers expect with cookie deprecation? Marketers face both operational and strategic hurdles as third-party cookies lose value. Addressability and targeting gaps Without universal identifiers, reaching audiences across channels becomes fragmented. Advertisers must unify data from CRM systems, mobile apps, and offline touchpoints to maintain reach. Measurement and attribution complexity As cookies disappear, so do last-click and view-through models. Solutions must rely on first-party data and probabilistic modeling to evaluate performance. Privacy and consent management Data collection now requires clear opt-ins, user control interfaces, and secure consent management systems that align with IAB standards. Resource and skill constraints Testing new identity and data solutions can be costly. Smaller teams may struggle to integrate clean rooms, universal IDs, or new reporting APIs. Experian’s role: Experian supports marketers through this transition with privacy-compliant data infrastructure, identity graphs, and measurement tools that work across every major platform. How can marketers adapt to a cookieless future? Cookies may still exist, but durable identity strategies are the future of digital marketing. Here’s how to prepare: Use first-party data: Collect information directly from your customers through loyalty programs, preference centers, and interactive content. Invest in analytics that translate this data into insight. Establish a trusted identity foundation: Experian’s Digital Graph connects more than 4.2 billion digital identifiers, linking households and devices in privacy-compliant ways. That means marketers can expand their addressable reach and understand audiences without relying on cookies. Experian’s data-collaboration solutions let you combine your first-party data with partner insights securely, unlocking deeper audience understanding. Explore alternative targeting technologies: Contextual methods powered by Experian’s data accuracy ranked #1 by Truthset, help you maintain personalization while respecting privacy. See how Experian’s identity resolution and data collaboration solutions can help you adapt in a cookieless world. What are the best practices for post-cookie marketing? Be transparent: Make consent simple and clear, and show how data adds value. Experian helps brands maintain transparency through privacy-first data solutions built on consented consumer information. Prioritize data quality: High-quality, verified data builds confidence and improves ROI. Experian’s accurate and validated data assets ensure marketers reach real people with relevant messages. Choose the right partners: Work with technology providers like Experian that support privacy regulations and enable interoperability across platforms. Keep the customer experience central: Relevance and respect earn long-term loyalty, values embedded in Experian’s approach to responsible marketing. What does the future look like for advertising without cookies? The end of cookies isn’t the end of personalization. It’s a chance to design advertising that earns consumer trust. Marketers who connect data responsibly and measure real outcomes will outperform those chasing outdated identifiers. Experian already helps global brands build this future through: Consumer Sync identity solution: Enables consistent, privacy-safe engagement across channels. Consumer View data solution: Delivers compliant, data-driven insights to inform data-driven marketing decisions. Digital and Offline Identity Graph: Provides scalable connectivity across digital and offline environments for a unified customer view. Learn how Experian can help you thrive after cookie deprecation Cookie deprecation changes how digital marketing works, but it doesn’t erase the value of data. With Experian’s identity, connectivity, and trust-based solutions, you can continue reaching audiences effectively and measure what matters. Explore how Experian can help you connect confidently in a cookieless world FAQs What is cookie deprecation? Cookie deprecation refers to browsers ending support for third-party cookies, which track users across sites. This shift promotes greater privacy and transparency while encouraging marketers to use first-party and identity-based data for targeting and measurement. Why is Google Chrome phasing out third-party cookies, and what’s changed recently? As of September 2025, Google paused its plan to fully deprecate third-party cookies in Chrome. The company will introduce new user privacy controls that allow individuals to choose how their data is shared, while continuing to test privacy-preserving APIs through its Privacy Sandbox. Which browsers are affected by third-party cookie deprecation? Safari and Firefox already block third-party cookies, and other browsers have adopted similar restrictions. While Chrome’s deprecation is paused, its large user base, more than 60 percent of global traffic, means its future policies will continue to influence how marketers plan and measure campaigns. How should marketers adapt to third-party cookie deprecation? Even with Google’s pause, marketers should keep building privacy-first strategies. Focus on:- Strengthening first-party data through loyalty programs and preference centers.- Using Experian’s Digital Graph to connect audiences across devices and environments.- Activating with Consumer Sync® for consistent, privacy-safe engagement.- Collaborating securely through Experian’s data collaboration solutions, which allow brands to share insights responsibly. Latest posts