
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.
Latest posts

Facebook has become a cultural phenomenon over the years and an object of affection for marketers to connect with its users. Experian Simmons has put together 10 consumer behavioral stats based on their National Consumer Study and New Media Study about the social networking site leading up to its Friday IPO launch: 39% of Facebook users say “this website gives me something to talk about.” Top 3 reasons Facebook users visit social networking sites: 86% to keep in touch with friends 72% for fun 66% to reconnect with/find people they’ve lost touch with 78% of Facebook users have shown support for a group or business on a social networking site. 34% of Facebook users have played games on a social networking site. Among those: 73% play social games (like Farmville, SIMS social, etc) 68% play casual games (like Bejeweled, etc) 73% play games on a social networking site once or more a day 28% of Facebook users with cell phones and 42% of Facebook users with a tablet computer have downloaded a social networking app for the device Adult residents of the following Designated Market Areas (DMAs) with 1,000,000 or more adult residents are the most likely to have visited Facebook in the last 7 days: ) Seattle-Tacoma, WA Austin, TX Salt Lake City, UT Portland, OR Washington, DC 15% of Facebook visitors follow a musical group on a social networking site, 14% follow a TV show, 11% follow a newspaper or news outlet and 4% follow a magazine. The average Facebook user is 39.3 years old. The average Facebook user claims an annual household income of $69,900 with annual household spending on discretionary goods and services of $15,500. Hispanic users of Facebook are 55% more likely than non-Hispanic users to say they like to follow their favorite brands or companies on social networking sites. Don’t miss 15 stats about Facebook, previously posted on the Experian Marketing services blog. . For more information like the data provided above please download the Experian Marketing Services 2012 Digital Marketer report.

Today, it costs more than $40 to send a five pound package from the U.S. to Canada or Mexico. The cost to Europe or South America is even more expensive. For U.S. companies operating on a global scale, such as retail specialists or ecommerce organizations, address accuracy is crucial. Organizations can’t afford undeliverable mail and packages due to a wrong address – the total cost would be unmanageable. Mistakes happen frequently, whether it is an error by the company or the customer. If a mistake is made, companies can’t ask the customer to cover delivery fees, leaving the organization with the bill. Retailers must also consider potential delays due to long distances and custom checks. Altogether, address errors result in a poor customer experience and a decrease in efficiency. Implementing international address verification will save money, time and improve the customer experience. By combining primary address data from national postal authorities with partner-supplied data, businesses can verify international addresses from countries all around the world.

On April 22nd, Americans and many of their terrestrial counterparts in countries around the world will celebrate Earth Day, a tradition that was started in the United States by Wisconsin Senator Gaylord Nelson in 1970. Much has changed on the planet since the first Earth Day, and even in recent years attitudes continue to evolve when it comes to our outlook towards the environment. In 2007, Experian Simmons created the GreenAware consumer segmentation, which classified respondents to the Simmons National Consumer Study between 2005 until 2007 into one of four mutually exclusive segments based on their consumer behaviors and attitudes toward the environment. Since then, Experian Simmons has continuously classified all adult respondents into the GreenAware segments providing our clients with valuable insights into the evolution of the environmental movement. The four GreenAware segments are: Behavioral Greens: This group of people thinks and acts green. They have negative attitudes towards products that pollute and incorporate green practices into their lives on a regular basis. Think Greens: This group of consumers think green, but don’t always act green. Potential Greens: This group neither behaves, nor thinks along particularly environmentally conscious lines and remains on the fence about key green issues. True Browns: They are not environmentally conscious, and may in fact have negative attitudes about environmental issues. Since 2005, we have observed a nearly constant increase in the percent of U.S. adults who are classified as Behavioral Greens, the “greenest” segment of the four. Today, 33% of adults are Behavioral Greens, up from 27% who were classified as such in 2005. Meantime, Think Greens have maintained an almost perfectly constant 21% share of the population. The size of the True Browns segment has also remained constant at between 14% and 15% of the total adult population. The Potential Green segment, however, has steadily declined in market share from 39% in 2005 to 31% today. La Vida Verde Hispanic Americans have traditionally been ahead of the curve when it comes to green thoughts and deeds and they’re only getting greener with time. Today, 39% of Hispanic adults are Behavioral Greens, up from 33% in 2007. Just 32% of non-Hispanic adults are Behavioral Greens today, up from 29% who fell into the greenest segment in 2007. Interestingly, among the True Browns segment there are virtually no Hispanics to be found, and, in fact, while the True Brown population is actually growing among non-Hispanics, Hispanics are increasingly moving to greener segments. Specifically, just 1.3% of Hispanics are True Browns today, down from 8% who registered as such in 2007. By comparison, 17% of non-Hispanics are True Browns today, up from 14% in 2007. Green Today, Greener Tomorrow? The illustration below shows the alignment of America’s largest metropolitan areas with the four GreenAware segments today and in 2007. We see that residents of the San Francisco-, New York- and Miami-areas are the most likely to be in alignment with the Behavioral Green mindset today. Denizens of Washington, D.C., Los Angeles, Chicago, Philadelphia and Boston tend to fit more closely with the Think Green set that has green attitudes and intentions, but not always the actions to back it up. But things are changing. In fact, since 2007, we’ve seen that as local minds change, some cities become aligned with a different, often greener, segment. Let’s look at Chicago, for instance. In 2007, Chicagoans’ environmental outlook was more reflective of a mix of Potential Greens and True Browns. Since then, local attitudes have changed so much that Chicago-area residents are now more aligned with Think Greens and Behavioral Greens. Likewise, Cleveland, which was clearly a True Brown town in 2007, now falls in step with the Potential Green segment. In five years’ time, who knows? Cleveland could be America’s next green leader. Not brown now towns Looking at markets large and small with the biggest drop in concentration of True Browns, we see that attitudes in inland markets located in Gulf States have become disproportionately less brown since the Deepwater Horizon oil spill in 2010. In fact, seven of the ten Designated Market Areas (DMA) that saw the biggest decline in the percentage of their population classified as True Browns between 2007 and 2011 are inland markets in states bordering the Gulf of Mexico. While the oil didn’t directly reach these markets, the attitude change did spread: For example, 3.2% of adults residing in the Columbus-Tupelo-West Point, Mississippi DMA today are classified as True Browns, down from 19.3% who were categorized as such in 2007. In Macon, Georgia, while not a Gulf State, a more impressive shift took place. In 2007, the Macon, Georgia DMA had the fourth highest percentage of its population classified as True Browns (20.1%) out of 209 DMAs. Today, only 5.8% of area residents are True Browns, which makes it the market with the 10th lowest concentrations of True Browns in the nation. Macon still has one of the lowest shares of residents who are Behavioral Greens in the nation, but what a difference a few years makes. While the towns directly in the path of the oil spill are not among those with the biggest relative decline in True Browns, area residents’ attitudes did take on a greener hue since the spill. Today, 8.4% of residents in Panama City are True Browns down from 17.3% in 2007. Likewise, only 9.8% of adults in both the Mobile-Pensacola and Biloxi Gulfport DMAs are True Browns down from 17.3% and 19.0%, respectively, who fell into the least green segment prior to the spill. Learn more about Experian Simmons consumer segmentation offerings