
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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The annual back-to-school season is in high gear and Moms are preparing lists and sizing up their children’s clothing and school-related merchandise needs. It’s an important time of year for retailers, as apparel, shoes, electronics, furniture, computers, backpacks and school supplies will account for the bulk of consumer spending during the back-to-school shopping season. Many marketers have historically grouped the back-to-school audience into one collective segment of households with school-age children. This leaves money on the table because there are better ways to target Moms with kids when developing a back-to-school promotional strategy. Just like the inventory of new clothes and notebooks that retailers have neatly arranged on store shelves, families with school-age children come in an assortment of sizes, shapes and colors. What is the most effective way to segment the back to school audience? This begs the question “” Marketers can always turn to basic data elements for segmentation. These include age and gender of children, number of children in the household, parent’s age, household income, and the full spectrum of school classifications (preschool, elementary school, middle school, junior high school, high school, etc.). Though a more powerful approach would be to utilize a segmentation methodology that recognizes the lifestyle and behavioral differences among households that are most likely to contain school-age kids. Here are three snapshots of family-oriented, children-centric market segments that are highly likely to be responsive to a wide variety of back to school promotional offers. All three segments have been selected from Experian’s Mosaic lifestyle segmentation solution. Babies and Bliss Description: Babies and Bliss represent the premier lifestyle for large families in America. With a majority of households containing at least five people, this segment is a haven for large broods living in new suburban subdivisions. Parents in this segment tend to be in their 30s and 40s. There is a wide range of kids in these households, from preschoolers up to those in high school. There is also money in this segment, reflecting the high educations and low six-figure incomes that come from dual earners employed in professional and technical occupations. Some key traits of Babies and Bliss households include upscale tastes, large families, well-educated, conservative views, financially-savvy, convenience, and power shopping. Implications: Given their large families, it's not surprising that Moms from Babies and Bliss households are value-conscious shoppers who seek appealing deals for quality merchandise. They carry coupons, like to comparison shop when buying expensive items and head to the clearance rack first whenever they buy clothes, which tend to be conservative in style. In the mall, these Moms follow their children's lead but also remain very open to consider generic store brands rather than high-priced name brands. They like to shop (it's practically a sport) and are happy to open their wallets at department stores, specialty shops, catalogs and online sites. They especially pride themselves in being very Internet-literate. With their jobs, kids and errands, they appreciate the convenience of shopping online and are receptive to email ads, sponsored Websites and Web page links. Families Matter Most Description: A fast-growing segment, Families Matter Most consists of young, middle-class families in suburban locations leading active, family-focused lives. Nine out of ten households have kids (nearly two-thirds have multiple kids). These young, middle-class families have settled into a landscape of recently built subdivisions. Many adult household members are urban exiles who've sought a suburban setting with room for kids to grow. They are proud of their new homes, schools and shopping centers, where they can find everything they need just a short drive away. Families Matter Most distinguish themselves by having adopted attitudes and routines to help them effectively juggle the responsibilities of work and child-rearing. Some key traits of Families Matter Most households include sprawling families, family values, casual perspectives, price-sensitivity, credit revolvers, conformists and risk avoidance. Implications: Families Matter Most are casual in their attitude except when it comes to their children. They take their role as parents very seriously, which they describe in conservative terms. They avoid risks and feel little need to make a statement with their possessions. As shoppers, Moms from Families Matter Most households are price-sensitive consumers who look for discount stores that offer durable and comfortable fashion. They are worried about spending money impulsively and try to be informed consumers. Most are happy to wear last year's fashions and they tend to zero in on a few stores that carry the affordable brands they prefer. With their growing families they shop most often at discount and mid-market national chains including Target, Walmart, Kohl's, Toys R Us and Old Navy. Cul de Sac Diversity Description: Cul de Sac Diversity consists of ethnically diverse, middle-aged couples with school-aged children. This segment has an above-average concentration of Hispanic and Asian household members. Nearly one-third of Cul de Sac Diversity adult members are foreign-born. They are three times more likely to be bilingual compared to U.S. adults overall. These upper-middle-class households are well on their way to achieving the American dream. 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Segmentation Layering For many marketers, segmentation is like breathing – it comes naturally and is a part of everything they do. To better connect with your target audience, use a good segmentation system with multiple layers that provides a breakdown of essential information while tying in lifestyle and transactional data. Consider marketing to parents. The most basic information includes demographics such as age, income, presence of children, etc. Add to that lifestyle information – the family has two working parents who rely heavily on the Internet for research and purchase convenience. The transactional data can really set apart where a parent falls on the parenting lifecycle. For example, is the parent still purchasing diapers and feeding supplies for their infant or bedding, towels and a coffee maker that might indicate their “baby” is headed to college? Both parents may look similar when comparing demographic and lifestyle information but the transactional data differentiates their needs. According to Experian Marketing Services: Parents use the Internet far more than the average American Moms are 34% more likely to buy products online and 33% more likely to participate in a blog than the average adult. "Marketers are targeting more carefully based on both the parents' life stage and consumer behavior,” says Jan Jindra, senior product market manager at Experian Marketing Services. “Younger parents, and those of smaller children, have different information needs than parents of older or college-age children. It's not only the life stage they're in, but the lifestyle," Jindra says. Read the full article and check out the latest in marketing to parents in DMNews: http://www.dmnews.com/household-brands-observe-parents-needs-in-defining-segmentation-tactics/article/205902/.