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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Privacy-forward pharma media supports more informed healthcare journeys Effective pharma marketing depends on reaching patients, caregivers, and healthcare professionals (HCPs) with useful information in appropriate, privacy-forward ways. The goal is to make relevant education easier to find, support more informed conversations, and help brands understand how media contributes across the health journey. In this Ask the Expert session, Natalie Mancuso, SVP, Data Partnerships at DeepIntent, joins Sheila Wirick, who leads the health team at Experian, to discuss how to craft patient and HCP campaigns, privacy-safe activation workflows, connected TV (CTV), and measurement approaches built for pharma. Why should your media plan start with understanding the patient and provider The patient-and-provider journey should inform your media plan, as treatment decisions in pharma are increasingly informed, personal, and patient-driven. With more health information available than ever, patients are playing a more active role in understanding their options and participating in treatment conversations. As other industries become more customer-centric, pharma media planning needs to become more patient-centric. “We’ve got patients who are more informed, more involved in their treatment decisions than ever. The accessibility of data and information and the ways we can consume it with just AI alone is so vast that if we’re not arming people with the right information in real time, we’re missing the boat.”Natalie Mancuso, SVP, Data Partnerships This means media should be aligned to where a patient or provider is in the decision journey and what they need at that moment. Early on, media may play an educational role by building awareness of a condition, symptom, or treatment category. Later, it may help support more specific questions, treatment consideration, access, affordability, or adherence. The patient-provider conversation remains the key boundary. That exchange should stay private and clinically led. Media can play a valuable role before and after those moments by offering information that helps patients and providers feel more informed. How can brands connect patient and HCP messaging responsibly? It’s critical for agencies and brands to deliver relevant messaging to inform each stakeholder’s needs throughout the treatment journey, especially ahead of key clinical milestones. To execute this, brands must exercise privacy-forward activation, keeping patient and HCP identity, activation, and measurement paths separate, while using a common workflow layer to support the same brand goal. Experian helps pharma marketers do this by acting as an independent, privacy-forward identity, data, and workflow layer. We bring together high-fidelity matching, governed onboarding, and non-clinical consumer context, so patient and HCP engagement can be activated more accurately across channels and connected to reporting. The distinction is not only where each audience is reached. HCPs may be engaged in both professional and personal environments, but their needs are different from patients’. For example, an HCP may receive messaging about co-pay savings for eligible patients, while a patient may receive information about patient support programs. These are different messages for different audiences, but they ladder up to the same goal: informing both parties in a privacy-forward, relevant way. Hear from Natalie Mancuso in our 2026 State of advertising report In our 2026 State of advertising report, Natalie shares why identity serves as the connective infrastructure that links planning, activation, and measurement across connected TV (CTV), programmatic, commerce media, and walled garden environments. Download the report Watch Natalie’s Q&A What does privacy-forward activation look like in pharma? Pharma brands often start with fragmented patient and HCP signals. Privacy-forward activation turns those inputs into usable audiences by first confirming that the data can be used, then translating identity in controlled environments that protect personally identifiable information through tokenization or other methodologies. For DTC, that means building and matching audiences without relying on inferred health conditions from browsing behavior. For HCPs, it means connecting professional identity to verified sources in a way that supports activation and measurement. In a category shaped by HIPAA, state privacy laws, internal review, and consumer sensitivity, building privacy in from sourcing through activation is what makes responsible health media possible. How can CTV play a more useful role in pharma? CTV can play a more useful role in healthcare when it’s connected to a larger, privacy-forward plan and not treated as just an awareness channel. DeepIntent connects CTV and digital exposure data using identity signals, such as National Provider Identifiers (NPIs), hashed email addresses, IP addresses, device IDs, and household signals, where permitted and reviewed. That identity layer helps support sequencing and suppression across streaming, endemic, mobile, and digital settings. In practice, CTV can introduce targeted education or broad brand awareness, and later touchpoints can provide sequential information in the right channels. Instead of repeating the same message, brands can make pivots based on engagement and context. “For us, it starts with identity and not panels. When we’re resolving CTV and digital exposures to the same person, we’re leveraging signals so that every touchpoint across streaming, endemic, and mobile is recognized as the same individual, not model lookalikes.”Natalie Mancuso, SVP, Data Partnerships For pharma, campaign performance should not be measured by reach alone. A stronger approach looks at whether sequenced engagement contributes to meaningful downstream signals, including: Prescription activity Provider engagement Referral patterns Patient compliance Adherence signals, where measurement is permitted Why should messaging and reporting change in pharma? Pharma campaigns are journeys with changing information needs. Reporting should guide the campaign optimization. “If I’m launching into a market with a new class of drug, I’m asking what education needs to be put into the market – from both an HCP and a consumer standpoint – to build awareness?”Natalie Mancuso, SVP, Data Partnerships Clicks and website visits still have a place, but they can’t tell the full pharma story. DeepIntent processes data in real time, giving brands an up-to-date read on how media connects to campaign engagement. Campaign signals can help teams optimize audience logic, creative, channel mix, or sequencing during a live campaign. Heading Test for Media & Text Block Content Test for Media &Text Block Learn more Heading Test for Media & Text Block Content Test for Media &Text Block Learn more Heading Test for Media & Text Block Content Test for Media &Text Block Learn more Explore how privacy-safe pharma activation can make an impact Experian brings marketing data and identity expertise for health marketing and DeepIntent adds pharma-specific activation experience. Together, we help brands connect patient and HCP strategies responsibly, with privacy built in from the start. Watch the full video with our experts to hear Sheila Wirick and Natalie Mancuso discuss patient and HCP messaging, CTV, privacy-safe activation, and outcome measurement for pharma brands. About our experts Natalie Mancuso SVP, Data Partnerships, DeepIntent Natalie Mancuso is SVP, Data Partnerships at DeepIntent and a leader in health-focused AdTech and DSP strategy. With over 20 years of experience growing billion-dollar healthcare brands, she turns complex data into scalable, performance-driven solutions that keep marketers ahead of industry change. Sheila Wirick Director of Health Sales, Experian Sheila Wirick is the Director of Health Sales at Experian with more than 20 years of experience in data and analytics. As Director of Health Sales at Experian Marketing Services, she collaborates with healthcare, pharmaceutical, and nonprofit organizations to apply data and insights that enhance customer retention, brand awareness, and acquisition. She is committed to helping organizations use data to deliver measurable results and meaningful impact. FAQs What makes a pharma audience activation-ready? A pharma audience is activation-ready when patient or HCP inputs can be translated into usable audiences with the right accuracy, controls, interoperability, and destination readiness. For patient engagement, that may include privacy-safe cohort construction, caregiver logic, non-clinical enrichment and appropriate exclusion rules. For HCP engagement, it may include governed identity inputs such as NPI, specialty, practice location, professional address and other verified attributes where appropriate. How can pharma brands sequence messages across channels responsibly? Pharma brands can sequence messages responsibly by giving each channel a clear role and using audience logic to maintain continuity. CTV and out-of-home can support awareness, social can reinforce the message, search can capture active research and point-of-care or rep-triggered channels can support decision moments. The workflow should preserve separation between patient and HCP identity strategies. What should pharma marketers measure beyond clicks and site visits? Pharma marketers should measure whether media connects to outcomes such as audience quality, prescription activity, qualified HCP engagement, verified delivery, referral patterns, therapy starts or adherence signals where permitted. These outcomes often depend on partner-enabled workflows, clean rooms, and aggregated outputs rather than direct end-to-end tracking. How does Experian help pharma brands connect identity, activation and measurement? Experian acts as an independent privacy-first identity, data, and workflow layer for pharma marketers. We help brands bring together identity, high-fidelity matching, governed onboarding, non-clinical consumer context, and partner interoperability so patient and HCP engagement can be activated more accurately across channels and connected more cleanly to partner-enabled measurement. Latest posts
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Use case #1: Identifying customer spending potential to boost growth for a retail chain Objective Solution Results The solution By syncing its cookies with the Digital Graph, the DSP gained access to related identifiers, including: This expanded identity universe gave the DSP a unified view of individuals and households, making it possible to connect impressions to conversions across devices and channels. With each weekly refresh, attribution models stayed accurate and up to date, turning fragmented signals into proof of performance. Results Within weeks, the DSP saw measurable improvements