
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.
Contact us
Latest posts

Healthcare and Life Sciences teams map the patient journey to spot care gaps and guide interventions. However, clinical records cover only what happens inside clinics, not the forces driving patient decisions. Enriching these records with lifestyle, socioeconomic, and consumer-behavior insights reveals the “why” behind health outcomes. That’s where non-clinical insights step in – revealing the real-world forces that shape patient results. To address these blind spots, Experian and Komodo Health have teamed to integrate de-identified insights from millions of patient journeys with Experian’s socioeconomic and lifestyle data. This enriched view lets enterprises see each journey in full, identify care disparities, and craft smarter strategies – while rigorously protecting privacy. Driving tangible outcomes and better patient care This collaboration focuses on turning insights into action. With Experian and Komodo's integrated clinical, socioeconomic, and lifestyle data, Healthcare and Life Sciences teams can move from insight to accuracy, building adherence programs, finding hard-to-reach patients, and demonstrating treatment success. They can: Layer Komodo’s de-identified patient-level medical and pharmacy insights and analytics with Experian lifestyle and socioeconomic attributes Segment patient populations by condition, treatment history, and socioeconomic status Prioritize outreach – reducing waste and focusing resources where care is needed most For instance: Neighborhood-level gaps Identify opportunities to capture untreated patients and improve clinical trial inclusion. Income-related support Flag populations most likely to benefit from cost-saving programs, ensuring communications highlight co-pay assistance or financial relief options. Inside the data stack At the core of Komodo Health's AI-enabled healthcare analytics platform is its Healthcare Map®. This innovative tool integrates de-identified patient-level medical and pharmacy claims data from the patient journeys of over 330 million unique individuals – providing insights on diagnoses, treatments, outcomes, and care patterns across the United States. Experian enhances this data by adding socioeconomic and lifestyle characteristics that influence up to 80% of health outcomes. Together, this combined data effectively addresses essential questions such as: Which neighborhoods face the highest diabetes risk? Where is therapy abandonment spiking? When should co-pay assistance messages drop? How can we accelerate HCP outreach or clinical-trial recruitment? Experian's socioeconomic and lifestyle insights: Fueling data-driven care decisions In this context, Experian provides valuable insights into socioeconomic factors and lifestyle patterns, covering everything from household composition and income ranges to psychographics and other attributes that help build a broader understanding of an individual's circumstances. Where deep patient understanding, health engagement, and real-world evidence converge As healthcare marketing, patient engagement, and real-world data converge, the Experian and Komodo collaboration is empowering Healthcare and Life Sciences teams with fast, actionable insights. Fusing de-identified patient-level clinical data with socioeconomic and lifestyle attributes helps teams engage the right patients, and fuels research from product launches to community programs. It elevates experiences while proving impact with real-world evidence. Ready to utilize these insights? Latest posts

Brand and tech leaders share insights to guide marketers forward Cannes Lions 2025 brought its usual charm, rosé, and lively discussions, but what stood out was a shift in tone: brand and tech leaders aren’t talking in theories anymore – they’re rebuilding how advertising works. From identity to outcomes, the consensus was clear: marketers need bold, structural changes to thrive. At Experian, we spoke with leaders from Ampersand, Butler/Till, Comcast Advertising, Fox, OpenX, Optable, Snowflake, VideoAmp, and Yieldmo. Their message? Foundational change, not incremental tweaks, is the way forward. Here are five moves marketers and CMOs should be making right now. 1. Make identity the foundation, not an add-on Identity must be the core of your marketing strategy, not an afterthought. Building a strong identity framework from the outset ensures that your data and tech stack work seamlessly across channels. This means investing in first-party data assets and identity resolution tools that inform every campaign and tactic. Identity isn’t just a feature; it’s the base layer of everything successful marketers do today. "There’s no AI strategy without a data and identity strategy. Marketers who want to stretch every media dollar and personalize each touchpoint need a unified, deeper view of the consumer – insight they can carry straight into downstream ad platforms.”David Wells, Snowflake Next step: Treat identity resolution as a prerequisite to every campaign, not a task to address later. Align your data management platform (DMP), customer data platform (CDP), and collaboration partners around a unified identity spine (Experian’s or your own) to ensure data flows uninterrupted from planning to reporting. 2. Curate, don't automate. Programmatic is getting personal Programmatic advertising remains relevant, but its purpose is evolving from mere automation to intelligent, data-driven curation. This shift requires moving beyond static site lists to dynamic, page-level contextual engines that determine, in real-time, which impressions to display. Today, it’s about carefully selecting and curating inventory to ensure transparency, quality, and relevance for your audience. Marketers are increasingly turning to private marketplaces (PMPs) that offer curated, brand safe inventory and clear supply paths to deliver meaningful results. Expect continued growth in curated PMPs, AI-assisted forecasting, and supply-side innovations that combine premium connected TV (CTV) inventory with deterministic data. The goal is to reach the right viewer and understand exactly how and why they got there. “What we’re talking about right now is almost like curation 2.0, which is bringing more of the capabilities that historically sat with the demand-side platform (DSP) into the hands of the supply-side platform (SSP) – that is, supply-side targeting, or what we call data-driven curation."Matt Sattel, OpenX Next step: Audit your supply chain. If you can’t clearly explain every step from bid request to delivery, explore curated deals or direct SSP partnerships that align with your quality and transparency standards. 3. Connect teams like you connect data Fragmented results often stem from fragmented teams. Persistent silos (like TV buys on one floor, digital on another, and data science somewhere else) slow down budgets and create inconsistent messaging. Forward thinking organizations are restructuring teams around unified KPIs and shared data. When planners, buyers, and analysts work together (or at least share dashboards), campaigns move faster and creative stays consistent. “We restructured our teams to focus on all forms of video – linear, streaming, and online. This allowed us to embrace partners who cross over these verticals and technical approaches.”Gina Whelehan, Butler/Till Next step: Map your current workflow end-to-end. Where does a brief stall or data stop flowing? Restructure teams or create shared success metrics to eliminate bottlenecks. 4. Turn disconnected data into unified insights Marketers have spent years gathering massive amounts of data, but hoarding data isn’t a winning strategy. The future belongs to those who can collaborate with partners to connect and utilize data effectively, all while respecting privacy and security. Rather than chasing the next data source, leading marketers are finding ways to safely connect data already available in-house or via partners. This might involve data clean rooms, secure data sharing agreements, or joint analytics initiatives – but the common thread is working together on data, not operating in isolation. “We've been encouraging marketers to tie in first-party data and to really utilize that data and to work with trusted sources and deterministic sources in order to overcome a lot of the challenges around signal loss with cookies, in particular. The other way is also clean rooms. Clean rooms really enable the opportunity to collaborate in a private, safe way, and connecting to those more deterministic sources in order to deliver the results that advertisers are looking for.”Carmela Fournier, Comcast Advertising Next step: Identify gaps in your first-party data. Then, collaborate with a provider like Experian to safely match data sets and unlock insights without exposing sensitive info. 5. Focus on outcomes, not clicks Impressions, clicks, and other output metrics have been the currency of marketing for decades. But the consensus at Cannes is that those proxies aren’t enough – business outcomes are what matter now. Marketers must shift their focus to measuring real results, such as sales lift, new customer acquisition, lifetime value, or brand impact, rather than getting bogged down in intermediate metrics. This move to outcome-based measurement changes how campaigns are planned and judged: success is defined by the value created, not just the volume delivered. Unified, identity-based analytics are finally making it possible to see who saw an ad and what they did next, across TV, CTV, and digital. That intel drives smarter budget shifts and tighter creative feedback loops. “Outcome-based measurement is table stakes in today’s media ecosystem, and Ampersand has woven it into almost everything we do. Thanks to Experian’s strength in identity, audience insights, and outcome measurement, we can give advertisers the attribution they need at every stage of the funnel.”Justin Rosen, Ampersand Next step: Identify metrics that matter to your bottom line, then find a partner who can measure them accurately. If measurement stacks don’t talk to each other, they’re holding you back. Preparing for the challenges ahead The common thread across these five moves is connection – connecting data, teams, and outcomes. Marketers who act on these imperatives will be ready for whatever new screen, format, or privacy rule comes next. Experian can help you: Establish an identity spine Enable secure data collaboration in or out of clean room environments Curate premium CTV inventory with deterministic audiences Measure business outcomes across every channel Ready to make your next bold move? Let's start a conversation Latest posts

Marketers are searching for better ways to connect with their audiences across screens and prove results. Optimum Media is at the forefront of this development, helping brands plan, activate, and measure campaigns across linear TV, addressable TV, connected TV (CTV), digital, and social platforms. To support this approach, Optimum Media partners with Experian, combining their subscriber data with Experian’s trusted audience and identity solutions. Together, we help brands not only find the right consumers but also understand their behaviors and measure real outcomes. Here’s how Optimum Media and Experian are working together. Build a complete customer view with rich data from Experian Optimum Media starts with strong first-party data, including viewership and exposure information from millions of households. However, reaching a deeper understanding of these audiences requires more than what subscriber records alone can offer. Through Experian’s Marketing Attributes, Optimum Media gains access to thousands of demographic and behavioral attributes to its data sets. These attributes—such as income ranges, lifestyle interests, and retail purchasing behaviors—help advertisers build a more complete view of the consumer. "We work with trusted partners like Experian to deliver the additional audience insights—like demographics and lifestyle—that are critical for our clients' success."Natalia Irmin, Sr. Director, Strategic Partnerships, Optimum Media Combining Experian’s Marketing Attributes with Optimum Media’s subscriber footprint helps brands segment audiences more precisely, develop refined media plans, and tailor messaging based on the real behaviors and interests of consumers. Move beyond basic targeting with Audience Engine To support more personalized and scalable targeting, Optimum Media uses Audience Engine—Experian’s self-service platform for audience management and activation. Through Audience Engine, Optimum Media can: Access Experian’s syndicated audiences Not just what’s available directly on their platform. Build custom segments Using Experian’s demographic and behavioral insights. Tap into our data marketplace To explore additional segments from Experian and our Partner Audiences through trusted third-party providers. These tools give Optimum Media and its clients the ability to move beyond basic targeting. Whether a brand wants to reach families preparing for back-to-school shopping, in-market car buyers, or upscale consumers planning home renovations, Audience Engine makes it possible to identify and activate those audiences with greater accuracy—based on real data, not guesswork. Extend campaign reach with Experian’s Digital Graph While Optimum Media has a substantial owned footprint, they often work with advertisers who need to extend reach beyond traditional subscriber bases. To support this, they rely on Experian’s Digital Graph. Our Digital Graph connects mobile ad IDs (MAIDs), IP addresses, CTV IDs, and hashed emails into unified household and individual profiles. This enables Optimum Media to identify and reach audiences outside of their network with the same level of accuracy as inside it. For even deeper audience insights, Digital Graph can be bundled with Marketing Attributes. This combination helps advertisers go beyond basic targeting to include real-world behaviors like shopping habits, travel preferences, and lifestyle characteristics. The result: campaigns that do more than deliver impressions—they connect with the right households across any channel. Turn viewership into measurable business outcomes One of the biggest challenges in multiscreen advertising is connecting exposure to real business results. With Experian’s solutions, Optimum Media can: Plan based on audience behaviors across screens, not just age and gender demographics. Activate household-level audiences across linear, CTV, digital, and social. Measure campaign performance using unduplicated reach, frequency, and attribution across devices. By offering advertisers access to a more complete consumer profile and maintaining consistent measurement across channels, Optimum Media and Experian help clients make better decisions about where to spend and how to adjust strategies over time. Why the Optimum Media and Experian partnership delivers Deeper audience understanding: By combining first-party viewership with Experian’s demographic and behavioral data, advertisers gain a fuller picture of who they are reaching. Seamless cross-platform execution: Identity solutions like Digital Graph allow brands to reach audiences across multiple devices and channels without losing precision. "Optimum Media has been instrumental in helping Experian strengthen the precision, quality, and real-world applications of our data. Their ongoing feedback is invaluable in making sure our solutions continue to meet client needs and perform at the highest level."Chris Feo, Chief Business Officer, Experian With a single, trusted partner offering both identity and audience solutions, Optimum Media avoids the complexity many advertisers still face when piecing together different data sets and vendors. “Having Experian’s identity and audience solutions under one roof makes it easier for us to plan, reach, and measure across every channel. It’s a complete solution that simplifies advertising and improves performance.”Natalia Irmin, Sr. Director, Strategic Partnerships, Optimum Media Start building better campaigns with Experian Ready to improve your audience targeting and measurement strategies like Optimum Media? Connect with our team today to learn how Marketing Attributes, Audience Engine, Digital Graph, and our other solutions can help you build stronger, more measurable advertising campaigns. Connect with us About Optimum Media Optimum Media is a multiscreen advertising business that partners with small and medium businesses, as well as national, political, media and entertainment, and agency clients across the United States. They work with advertisers to develop custom multiscreen advertising solutions powered by proprietary technology and a massive aggregated database of audience data points and TV viewership data. Latest posts