
We’re excited to introduce the next segment in our Q&A series, Ask the Expert! Ask the Expert features a series of conversations with product experts where we dive into the areas you care most about like identity resolution, targeting, attribution, and more. Our next segment features a conversation about sell-side targeting.
Mike Chowla, SVP of Product at OpenX joins us to chat with Experian’s SVP of Sales & Partnerships, Chris Feo. OpenX is the world’s leading sell-side platform for audience, data, and identity targeting. In their conversation, Mike and Chris review:
- The shift to targeting on the sell-side
- How first- and third-party data are being used on the sell-side
- How OpenX is thinking about alternative IDs

What is sell-side targeting?
Sell-side targeting optimizes the way buyers and supply-side platforms (SSPs) work together. This approach moves the responsibility of inventory and audience targeting from the demand-side platform (DSP) into the SSP, providing advertisers with increased reach and better performance.
With sell-side targeting, locating your target audience becomes easier as you have a more direct connection with publishers. This increases your ability to scale against a target audience. Specifically, the SSP directly matches the buyer’s audience or data segment to the publisher inventory and audience and automatically sends the impression to the buyer’s DSP of choice via a deal ID, providing advertisers with improved reach and performance metrics as well as control over their inventory. With more direct access, your budget can likely go further, and you can decrease your effective cost per mille (eCPM) and get more working media.
“Supply-side targeting is the next phase of how supply path optimization (SPO) and buyers will need to work more closely with SSPs.” – Mike Chowla, SVP, Product, OpenX
Buying on the sell-side vs. open exchange
When buying on the open exchange, you have access to a vast number of impressions. With sell-side targeting, you can apply your campaign targeting directly on the supply-side and activate those impressions through a deal ID. Sell-side targeting works across various formats including web display, mobile, in-app, and connected TV (CTV) for a seamless advertising experience.
OpenX offers the unique capability to match users using their device graph within their SSP. This means you can target users from traditional data sources such as cookies or mobile ad IDs (MAIDs) and reach them in CTV or app environments. This gives you even more reach and precision in your advertising efforts.
The role of first- and third-party data on the sell-side
Buyers are showing a keen interest in bringing their own first-party data into the process of sell-side targeting. Meanwhile, certain agencies have been actively involved in working with identity and data. OpenX is currently collaborating with several agency ID solutions such as Choreograph, Merkel, and Horizon.
Buyers are also purchasing third-party data and data segments from various providers through OpenX’s platform for sell-side targeting purposes. By utilizing this data on the supply side, buyers are able to increase the match rate against their first- and third-party data segments in all environments. This ultimately maximizes scale against these audiences and drives a more efficient CPM due to eliminating waste.
Measurement and attribution on the sell-side
In the current state of SSP advertising, there is more of an emphasis on targeting capabilities than measurement and attribution. That said, SSPs can provide granular log level reports that can be utilized for multi-touch attribution (MTA) or mixed media models (MMM). These granular insights not only inform measurement and attribution models, but they also provide valuable optimization insights such as clearing price.
Additionally, advertisers have all of the same reporting options that they’re used to getting through their DSP because their buys are activated via deal ID in the DSP of their choice.
What to consider when transitioning to sell-side targeting
There are two primary items you should consider when transitioning to sell-side targeting:
- Supply
- Reach
Reach
Collaborating with partners who have the right capabilities can greatly improve reach and audience extension across different devices. For instance, if you bring your first-party audience or a third-party audience and are identifying that consumer via a cookie or MAID, being able to extend that targeting segment to other devices and platforms can be highly beneficial.
Supply
It’s crucial to collaborate with partners who have the right access to supply and direct connections with publishers. While targeting is essential, it’s equally important to have high-quality supply to drive performance.
Reaching consumers in a cookieless future
Whether you’re targeting on the demand or sell-side, it always starts with the consumer and who you’re trying to reach.
Significant changes in the consumer privacy landscape are impacting advertisers’ ability to access various signals emitted by consumers through their devices and browsers. Recent developments from Apple and Google have further amplified this situation.
Alternative IDs as a solution to signal loss
In response, we’re seeing the emergence of alternative IDs like UID2, Ramp ID, and ID5. OpenX supports these types of IDs and considers them crucial for audience buying in a privacy-centric cookie-less future.
We are still in the early stages of this evolution. While some of the IDs have good coverage, cookies will continue to be the primary targeting method as long as they remain available.
Nevertheless, we see alternative IDs as one of several solutions that will become increasingly important as third-party cookies disappear. Contextual buying will also emerge, and a set of solutions will come together to enable advertisers to keep finding their audience in a cookie-less world.
Overcoming signal loss with identity resolution
Looking ahead, as we continue to lose signals due to the evolving consumer privacy landscape, we will witness two things:
- Continued fragmentation
- A wide variety of identifiers
Content will continue to be available on various devices. We’re currently experiencing the emergence of connected TV, but who knows what other devices will surface over the next five to ten years. As cookies disappear, which have been the primary identifier, and alternative IDs are introduced, the wide variety of identifiers will create further fragmentation. This highlights the need for identity in the future.
Identity resolution at Experian matches fragmented identifiers to a single profile to create a unified, cross-channel view of your consumers. Our identity resolution solutions can help future-proof your marketing strategies.
How Experian and OpenX work together
Experian is a key player in OpenX’s OpenAudience solution and helps to power many of their data segments as well as their identity graph. While OpenX collaborates with a variety of providers and operates a fully interoperable platform, Experian remains valuable to the core technology within OpenX’s SSP.
“Experian powers a lot of the data segments and identity graph that OpenX has in our OpenAudience capabilities as part of our SSP.” – Mike Chowla, SVP, Product, OpenX
Watch the full Q&A
Visit our Ask the Expert content hub to watch Mike and Chris’s full conversation on sell-side targeting. In the Q&A, Mike and Chris also share their thoughts on the impact artificial intelligence (AI) will have on the AdTech industry and their go-to sources for staying up to date on all things AdTech.
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About our experts

Mike Chowla, SVP, Product, OpenX
Mike Chowla is the SVP of Product at OpenX where he leads product development and innovation, from customer discovery and user research to the development, delivery, and support of a market-leading product suite. Chowla holds a BS in Engineering from the University of Southern California, and an MBA from The University of Pennsylvania.

Chris Feo, Chief Business Officer, Experian
As SVP of Sales & Partnerships, Chris has over a decade of experience across identity, data, and programmatic. Chris joined Experian during the Tapad acquisition in November 2020. He joined Tapad with less than 10 employees and has been part of the executive team through both the Telenor and Experian acquisitions. He’s an active advisor, board member, and investor within the AdTech ecosystem. Outside of work, he’s a die-hard golfer, frequent traveler, and husband to his wife, two dogs, and two goats!
Latest posts

Contextual ad targeting paves the way for new opportunities Advertisers and marketers are always looking for ways to remain competitive in the current digital landscape. The challenge of signal loss continues to prompt marketers to rethink their current and future strategies. With many major browsers phasing out support for third-party cookies due to privacy and data security concerns, marketers will need to find new ways to identify and reach their target audience. Contextual ad targeting offers an innovative solution; a way to combine contextual signals with machine learning to engage with your consumers more deeply through highly targeted accuracy. Contextual advertising can help you reach your desired audiences amidst signal loss – but what exactly is contextual advertising, and how can it help optimize digital ad success? In a Q&A with our experts, Jason Andersen, Senior Director of Strategic Initiatives and Partner Solutions with Experian, and Alex Johnston, Principal Product Manager with Yieldmo, they explore: The challenges causing marketers to rethink their current strategies How contextual advertising addresses signal loss Why addressability is more important than ever Why good creative is still integral in digital marketing Tips for digital ad success By understanding what contextual advertising can offer, you’ll be on the path toward creating powerful, effective campaigns that will engage your target audiences. Check out Jason and Alex’s full conversation from our webinar, “Making the Most of Your Digital Ad Budget With Contextual Advertising and Audience Insights” by reading below. Or watch the full webinar recording now! Watch now Macro impacts affecting marketers How important is it for digital marketers to stay informed about the changes coming to third-party cookies, and what challenges do you see signal loss creating? Jason: Marketers must stay informed to succeed as the digital marketing landscape continuously evolves. Third-party cookies have already been eliminated from Firefox, Safari, and other browsers, while Chrome has held out. It's just a matter of time before Chrome eliminates them too. Being proactive now by predicting potential impacts will be essential for maintaining growth when the third-party cookie finally disappears. Alex: Jason, I think you nailed it. Third-party cookie loss is already a reality. As regulations like the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA) take effect, more than 50% of exchange traffic lacks associated identifiers. This means that marketers have to think differently about how they reach their audiences in an environment with fewer data points available for targeting purposes. It's no longer something to consider at some point down the line – it's here now! Also, as third-party cookies become more limited, reaching users online is becoming increasingly complex and competitive. Without access to as much data, the CPMs (cost per thousand impressions) that advertisers must pay are skyrocketing because everyone is trying to bid on those same valuable consumers. It's essential for businesses desiring success in digital advertising now more than ever before. Contextual ad targeting: A solution for signal loss How does contextual ad targeting help digital marketers find new ways to reach and engage with consumers? What can you share about some new strategies that have modernized marketing, such as machine learning and Artificial Intelligence (AI)? Jason: We're taking contextual marketing to the next level with advanced machine learning. We are unlocking new insights from data beyond what a single page can tell us about users. As third-party cookies go away, alternative identifiers are coming to market, like RampID and UID2. These are going to be particularly important for marketers to be able to utilize. As cookie syncing becomes outdated, marketers will have to look for alternative methods to reach their target audiences. It's essential to look beyond cookie-reliant solutions and use other options available regarding advertising. Alex: I think, as Jason alluded to, there's a renaissance in contextual advertising over the last couple of years. If I were to break this down, there are three core drivers: The loss of identity signals. It's forcing us to change, and we must look elsewhere and figure out how to reach our audiences differently. There have been considerable advances in our ability to store and operate across a set of contextual signals far more extensive than anything we've ever worked with in the past and in far more granular ways. That's a huge deal because when it comes to machine learning, the power and the impact of those machine learning models are entirely based on how extensive and granular the data set is that you can collect. Machine learning can pull together critical contextual signals and figure out which constellations, or which combinations of those signals, are most predictive and valuable to a given advertiser. We can tailor machine learning models to individual advertisers using all those signals and find patterns across those in ways that were previously impractical or unfeasible. The transformation is occurring because of our ability to capture much more granular data, operate across it, and then build models that work for advertisers. Addressability: Connect your campaigns to consumers How does advanced contextual targeting help marketers reach non-addressable audiences? Jason: Advanced contextual targeting allows us to take a set of known data (identity) and draw inferences from it with all the other signals we see across the bitstream. It's taking that small seed set of either, customers that transacted with you before that you have an identity for, or customers that match whom you're looking for. We can use that as a seed set to train these new contextual models. We can now look at making the unknown known or the unaddressable addressable. So, it's not addressable in an identity sense, it is addressable in a contextual or an advanced contextual sense that's made available to us, and we can derive great insight from it. One of the terms I like to use is contextual indexing. This is where we take a set of users we know something about. So, I may know the identity of a particular group of households, and I can look at how those households index against any of the rich data sets available to us in any data marketplace, for example, the data Yieldmo has. We can look at how that data indexes to those known users to find patterns in that data and then extrapolate from that. Now we can go out and find users surfing on any of the other sites that traditionally don't have that identifier for that user or don't at that moment in time and start to be able to advertise to them based on the contextually indexed data. Historically, we've done some contextual ad targeting based on geo-contextual, and this is when people wanted to do one to one marketing, and geo-contextual outperformed the one to one. But marketers weren't ready for alternatives to one to one yet. We want marketers to start testing these solutions. Advertisers must start trying them, learning how they work, and learn how to optimize them because they are based on a feedback loop, and they're only going to get better with feedback. Alex: Jason, you described that perfectly. I think the exciting opportunity for many people in the industry is figuring out how to reach your known audience in a non-addressable space, that is based on environmental and non-identity based signals, that helps your campaign perform. Your known audience are people that are already converting – those who like your products and services and are engaged with your ads. Machine learning advancements allow you to take your small sample audience and uncover those patterns in the non-addressable space. It's also worth noting that in this world in which we are using seed audiences, or you are using your performing audiences to build non-addressable counterpart targeting campaigns, having high-quality, privacy-resilient data sets becomes incredibly important. In many cases, companies like Experian, who have high quality, deep rich training data, are well positioned to support advertisers in building those extension audiences. As we see the industry evolve, we're going to see some significant changes in terms of the types of, and ways in which, companies offer data, and make that available to advertisers for training their models or supporting validation and measurement of those models. Jason: Addressable users, the new identity-based users, are critical to marketers' performance initiatives. They're essential to training the models we're building with contextual advertising. Together, addressable users and contextual advertising are a powerful combination. It's not just one in isolation. It's not just using advanced contextual, and it's not just using the new identifiers. It's using a combination to meet your performance needs. It's imperative to start thinking about how you can begin building your seed audiences. What can you start learning from, and how do you put contextual into play today? You are looking to build off a known set and build a more advanced model. These can be specialized models based on your data. You can hone in and create a customized model for your customer type, their profile, and how they transact. It's a greenfield opportunity, and we're super excited about the future of advanced contextual targeting. Turn great creative into measurable data points Why does good creative still play an integral part in digital advertising success? Jason: Good creative has always been meaningful. It's vital in getting people to click on your ad and transact. But it's becoming increasingly important in this new world that we're talking about, this advanced contextual world. The more signal that we can get coming into these models, the better. Good creative in the proper ad format that you can test and learn from is paramount. It comes back to that feedback loop. We can use that as another signal in this equation to develop and refine the right set of audiences for your targeting needs. Alex: If you imagine within the broader context of identity and signal loss, creative and ad format becomes incredibly powerful signals in understanding how different audiences interact with and engage with different creative. In the case of the formats that serve on the Yieldmo exchange, we're collecting data every 200 milliseconds around how individual users are engaging with those ads. Interaction data like the user scrolling back or the number of pixel seconds they stay on the screen, fills this critical gap between video completes and clicks. Clicks are sparse and down the funnel, and views and completes are up the funnel. All those attention and creative engagement type metrics occupy the sweet spot where they're super prevalent, and you can collect them and understand how different audiences engage with your ads. That data lets you build powerful models because they predict all kinds of other downstream actions. Throughout my career, I learned that designing or tailoring your creative to different audience groups is one of the best ways to improve performance. We ran many lift studies with analysis to understand how you can tailor creative customized for individual audiences. That capability and the ability to do that on an identity basis is starting to deteriorate. The ability to do that using a sample of data or using a smaller set of users, either where you're inferring characteristics or you're looking at the identity that does exist in a smaller group, becomes powerful for being able to customize your creative to tell the right story to the right audience. When you layer together all the interaction data collected at the creative level on top of all the contextual and environmental signals, you can build powerful models. Whether those are driving proxy metrics, or downstream outcomes, puts us in a powerful position to respond to the broader loss of identity that we've relied on for so many years. Our recommendations for marketers for 2023 and beyond Do you have recommendations for marketers building out their yearly strategies or a campaign strategy? Jason: Be proactive and start testing and learning these new solutions. I mentioned addressability and being in the right place at the right time. That's easier in today's third-party cookie world. But as traditional identity is further constricted, you will have these first-party solutions that will not be at scale, so you're less likely to find your user at the scale you want. It would be best if you thought about how to reach that user at the right place at the right time. They may not be seen from an identity basis. They might not be at the right place at the right time when you were delivering or trying to deliver an ad. But you increase your chance of reaching them by building these advanced contextual targeting audiences using this privacy-safe seed 'opted-in' user set; this is a way to cast that wider net and achieve targeted scale. Alex: Build your seed lists, test your formats with different audiences, and understand what's resonating with whom. Take advantage of some of the pretty remarkable advances in machine learning that are allowing us, really, for the first time to fully uncork the potential and the opportunity with contextual in a way that we've never done before. Jason: At the end of the day, it's making the unaddressable addressable. So, it's a complementary strategy; having that addressable piece will feed the models. But also, that addressable piece still needs to be identity-based, addressable still needs to be part of your overall marketing strategy, and you need to complement it with other strategies like advanced contextual targeting. The two of them together are super complimentary. They learn from each other, and it's a cyclical loop. Now is the time to take advantage and start testing and understanding how these solutions work. We can help you get started with contextual ad targeting Contextual advertising can help you stay ahead of the curve, identify your target audience, and continue to drive conversions despite signal loss. We've partnered with Yieldmo to help make sure that your marketing campaigns are reaching the right target audiences on the platforms that are most relevant. To get started with contextual ad targeting to reach the right audience at the right time and drive conversions, contact our marketing professionals. Let's get to work, together. Contact us today Find the right marketing mix in 2023 Check out our webinar, "Find the right marketing mix with rising consumer expectations." Guest speaker, Nikhil Lai, Senior Analyst from Forrester Research, joins Experian experts Erin Haselkorn, and Eden Wilbur. We discuss: New data on the complexity and uncertainty facing marketers Consumer trends for 2023 Recommendations on finding the right channel mix and the right consumers Watch now Get in touch About our experts Jason Andersen, Senior Director, Strategic Initiatives and Partner Solutions, ExperianJason Andersen heads Strategic Initiatives and Partner Enablement for Experian Marketing Services. He focuses on addressability and activation in digital marketing and working with partners to solve signal loss. Jason has worked in digital advertising for 15+ years, spanning roles from operations and product to strategy and partnerships. Alex Johnston, Principal Product Manager, YieldmoAlex Johnston is the Principal Product Manager at Yieldmo, overseeing the Machine Learning and Optimization products. Before joining Yieldmo, Alex spent 13 years at Google, where he led the Reach & Audience Planning and Measurement products, overseeing a 10X increase in revenue. During his time, he launched numerous ad products, including YouTube's Google Preferred offering. To learn more about Yieldmo, visit www.Yieldmo.com. Latest posts

In 2022, Google began changing the availability of the information available in User-Agent strings across their Chromium browsers. The change is to use the set of HTTP request header fields called Client Hints. Through this process, a server can request, and if approved by the client, receive information that would have been previously freely available in the User-Agent string. This change is likely to have an impact on publishers across the open web that may use User-Agent information today. To explain what this change means, how it will impact the AdTech industry, and what you can do to prepare, we spoke with Nate West, our Director of Product. What is the difference between User-Agents and Client Hints? A User-Agent (UA) is a string, or line of text, that identifies information about a web server’s browser and operating system. For example, it can indicate if a device is on Safari on a Mac or Chrome on Windows. Here is an example UA string from a Mac laptop running Chrome: To limit the passive fingerprinting of users, Google is reducing components of the UA strings in their Chromium browsers and introducing Client Hints. When there is a trusted relationship between first-party domain owners and third-party servers, Client Hints can be used to share the same data. This transition began in early 2022 with bigger expected changes beginning in February 2023. You can see in the above example, Chrome/109.0.0.0, where browser version information is already no longer available from the UA string on this desktop Chrome browser. How can you use User-Agent device attributes today? UA string information can be used for a variety of reasons. It is a component in web servers that has been available for decades. In the AdTech space, it can be used in various ad targeting use cases. It can be used by publishers to better understand their audience. The shift to limit access and information shared is to prevent nefarious usage of the data. What are the benefits of Client Hints? By using Client Hints, a domain owner, or publisher, can manage access to data activity that occurs on their web properties. Having that control may be advantageous. The format of the information shared is also cleaner than parsing a string from User-Agents. Although, given that Client Hints are not the norm across all browsers, a long-term solution may be needed to manage UA strings and Client Hints. An advantage of capturing and sharing Client Hint information is to be prepared and understand if there is any impact to your systems and processes. This will help with the currently planned transition by Google, but also should the full UA string become further restricted. Who will be impacted by this change? Publishers across the open web should lean in to understand this change and any potential impact to them. The programmatic ecosystem supporting real-time bidding (RTB) needs to continue pushing for adoption of OpenRTB 2.6, which supports the passing of client hint information in place of data from UA strings. What is Google’s timeline for implementing Client Hints? Source: Google Do businesses have to implement Client Hints? What happens if they don’t? Not capturing and sharing with trusted partners can impact capabilities in place today. Given Chromium browsers account for a sizable portion of web traffic, the impact will vary for each publisher and tech company in the ecosystem. I would assess how UA strings are in use today, where you may have security concerns or not, and look to get more information on how to maintain data sharing with trusted partners. We can help you adopt Client Hints Reach out to our Customer Success team at tapadcustomersuccess@experian.com to explore the best options to handle the User-Agent changes and implement Client Hints. As leaders in the AdTech space, we’re here to help you successfully make this transition. Together we can review the options available to put you and your team on the best path forward. Get in touch About our expert Nate West, Director of Product Nate West joined Experian in 2022 as the Director of Product for our identity graph. Nate focuses on making sure our partners maintain and grow identity resolution solutions today in an ever-changing future state. He has over a decade of experience working for media organizations and AdTech platforms. Latest posts

Up next in our Ask the Expert series, Ben Rothke, Senior Information Security Manager, reviews two certifications that should be part of your information security strategy: Service Organization Control (SOC) 2 Type 2 and International Organization for Standardization (ISO) 27001. Tapad, a part of Experian, is 27001 and SOC 2 Type 2 compliant. Two information security certifications you can trust Seals from Good Housekeeping and Underwriters Laboratories give consumers confidence that they can trust the product that they’re buying. For IT solutions or service providers, what, or who can you turn to for that seal of approval? There are many equivalent third-party attestations you can use. But which should you trust? The International Organization for Standardization (ISO) 27001 The American Institute of Certified Public Accountants (AICPA) System and Organization Controls (SOC) International Organization for Standardization (ISO) 27001 is an international standard for information security from the ISO. ISO 27001 is globally acknowledged and sets requirements for controls, maintenance, and certification of an information security management system (ISMS). This international standard provides organizations with a framework to identify, manage and reduce risks related to the security of information System and Organization Controls (SOC) The SOC, as defined by the AICPA, is a set of audit reports. SOC reports, like 27001 certificates, are used by service organizations to give their customers the confidence they have adequate information security controls in place to protect the data that they handle. SOC 2 is an assessment of controls at a service organization regarding security, availability, processing integrity, confidentiality, and privacy. The purpose of the report is to provide extensive information and assurance to a broad range of users about the controls at a service organization that are relevant to the security, availability, and processing integrity of the systems that process user data, as well as the confidentiality and privacy of the information processed by these systems. Why ISO 27001 and SOC 2 are important The value of these third-party attestations is two-fold: Organizations can show they have passed an independent external audit Third-party attestations save organizations the time of having to do their own audits In addition to 27001 and SOC 2 Type 2 compliance, we are also certified with ISO 27017 and 27018, which are add-ons to 27001 that are specific to cloud computing. We take the security and privacy of our customers’ data as seriously as they do. Every cloud service provider (CSP) has a responsibility matrix that details what security and privacy tasks they are responsible for and which ones the customer is responsible for. Any cloud customer that needs to be made aware of what their security tasks are is putting themselves at risk. So, when you want to engage a CSP, ask them for their attestations. They worked hard for them and will be proud to share their compliance. We’re powered by decades of setting standards in marketing services At Experian, we’re a privacy-first business. We’re highly focused on respecting people, their data, and their privacy. We continue to show our dedication to information security by completing these security audits every year. The constant changes to data compliance regulations can be challenging to navigate, but you don’t have to do it alone. Contact us today. We will be your guide so you can ethically and confidently reach your customers. Contact us today Contact us today About our expert Ben Rothke, Senior Information Security Manager Ben Rothke, CISSP, CISA, is a Senior Information Security Manager at Tapad, a part of Experian. He has over 25 years of industry experience in information systems security and privacy. His areas of expertise are in risk management and mitigation, security and privacy regulatory issues, cryptography, and security policy development. Ben is the author of Computer Security – 20 Things Every Employee Should Know (McGraw-Hill), and writes security and privacy book reviews for the RSA Conference Blog and Security Management magazine. Latest posts