Programmatic advertising is becoming increasingly fragmented across connected TV, mobile apps and the open web, making supply quality harder for advertisers to evaluate consistently. Pixalate’s Q1 2023 Seller Trust Indexes provide a comparative view of programmatic sellers across those environments, ranking companies according to factors associated with supply-chain quality and integrity.
The programmatic advertising ecosystem has a scale problem—and increasingly, a transparency problem.
As media buying expands across connected TV (CTV), mobile applications and desktop and mobile websites, advertisers can encounter thousands of sellers and supply paths when purchasing a single campaign. Understanding which sellers provide higher-quality inventory has therefore become an important part of supply-path optimization.
Pixalate’s latest Seller Trust Indexes (STIs) attempt to address that challenge by ranking programmatic sellers across three major advertising environments: CTV, mobile in-app advertising and web advertising.
The Q1 2023 indexes cover the CTV Seller Trust Index, Mobile Seller Trust Index and Web Seller Trust Index. Pixalate evaluates sellers using multiple factors intended to measure the quality and integrity of participants in the programmatic supply chain.
Rather than treating all inventory as interchangeable, the indexes give advertisers and publishers another framework for evaluating the companies sitting between buyers and media owners.
CTV rankings reveal a fragmented supply chain
CTV is one of the fastest-changing parts of the programmatic market, but its infrastructure remains fragmented across device manufacturers, streaming platforms, publishers, SSPs and other intermediaries.
Pixalate’s Q1 rankings illustrate that fragmentation.
On Roku, Magnite and FreeWheel tied for first place with final scores of 85. OpenX and EMX followed at 84, while Unruly ranked fifth with 82.
On Amazon Fire TV, Index Exchange led with a score of 91, followed by EMX at 90 and OpenX at 89. TripleLift and FreeWheel rounded out the top five at 88.
The Samsung rankings produced another variation. FreeWheel ranked first at 91, Magnite followed at 88 and OpenX scored 87. Unruly and TripleLift completed the top five at 86 and 85, respectively.
The differences across devices highlight an important characteristic of CTV advertising: there is no single universal supply hierarchy.
A seller that performs strongly on one CTV ecosystem may not occupy the same position on another because inventory sources, platform relationships and supply paths vary.
For advertisers buying CTV programmatically, that makes device-level and platform-level supply analysis increasingly relevant.
Mobile brings a different set of supply challenges
The Mobile Seller Trust Index focuses on programmatic in-app advertising.
MobileFuse ranked first with a score of 91, followed by IronSource at 90. OpenX, VRTCAL and Luna Media tied for third with scores of 89.
The mobile market presents a different quality-control challenge from CTV.
In-app advertising operates across a vast number of applications, developers and ad networks, making transparency and inventory validation particularly important. Advertisers must contend with issues including invalid traffic, app-ads.txt compliance, spoofing, privacy requirements and discrepancies between declared and actual inventory.
An independent ranking can therefore provide buyers with an additional reference point when assessing supply partners.
However, a seller ranking should not be interpreted as a complete measure of campaign performance. Advertisers still need to evaluate individual inventory sources based on audience quality, viewability, fraud rates, conversion performance, privacy compliance and business objectives.
Web sellers compete on a mature but complicated market
The Web Seller Trust Index covers programmatic desktop and mobile web advertising inventory in the U.S.
Sharethrough and Sovrn tied for first place at 88, while Yahoo ranked third at 87. Index Exchange followed at 85 and PubMatic at 84.
The web ecosystem has had decades to develop programmatic infrastructure, but that maturity has also produced complex supply chains.
A single impression can pass through multiple intermediaries, each potentially adding fees and latency while making the final media path more difficult for advertisers to understand.
That has fueled the growth of supply-path optimization (SPO), where advertisers and agencies attempt to identify efficient, transparent routes to publisher inventory.
Seller quality rankings can contribute to that process by providing another layer of intelligence when buyers assess which SSPs and exchanges deserve greater investment.
Trust is becoming an AdTech buying criterion
Pixalate’s rankings arrive amid a wider shift in how advertisers evaluate programmatic media.
Historically, buying decisions focused heavily on reach, CPM and audience targeting. Today, media buyers increasingly consider supply-chain transparency, fraud prevention, privacy compliance, brand safety, inventory quality and operational efficiency.
The emergence of initiatives such as ads.txt, app-ads.txt and sellers.json has also given buyers more tools for understanding who is authorized to sell particular inventory.
CTV adds another layer of complexity because streaming inventory is distributed through device ecosystems and connected-TV platforms that do not always operate like traditional web advertising.
That makes standardized measurement and seller evaluation particularly important.
For enterprise advertisers, the practical value of the Seller Trust Indexes is therefore less about selecting a single “best” seller and more about incorporating supply quality into procurement and optimization decisions.
A global campaign might use different SSPs for Roku, Fire TV and Samsung inventory. Similarly, mobile app campaigns may require a separate supply strategy from desktop web campaigns.
Competition is moving toward supply quality
The companies appearing in Pixalate’s rankings—including Magnite, FreeWheel, OpenX, Index Exchange, TripleLift, PubMatic and Yahoo—represent a broad cross-section of the modern programmatic ecosystem.
They compete not only for advertiser budgets but also for publisher relationships and increasingly for trust.
That competition could become more important as advertisers demand greater visibility into the path their money takes from DSP to publisher.
For SSPs, quality measurement can become a competitive differentiator. For agencies, it can inform supply-path decisions. For publishers, it can influence which partners they prioritize for monetization.
The broader direction of the market is clear: programmatic scale alone is no longer enough.
Advertisers want efficient access to quality inventory, but they also want confidence that the inventory is legitimate, measurable and compliant.
Pixalate’s Q1 2023 Seller Trust Indexes provide one snapshot of that evolving market. The more important trend is the growing expectation that programmatic advertising should be evaluated not just by how much inventory it can access, but by the quality and integrity of the path used to reach it.
Market Landscape
The rise of CTV, mobile programmatic advertising and supply-path optimization is making seller transparency a central issue in AdTech.
CTV is particularly fragmented, with Roku, Amazon Fire TV and Samsung operating distinct environments. Meanwhile, mobile in-app advertising involves thousands of apps and publishers, while web advertising continues to rely on a complex network of SSPs, exchanges and intermediaries.
This creates an opening for measurement and analytics platforms that can evaluate sellers across multiple dimensions.
Major advertising ecosystems such as Google, Amazon and Microsoft are also emphasizing supply quality, privacy and measurement as advertisers demand greater control over where their budgets are spent.
The next phase of programmatic optimization is likely to combine audience performance, media quality, supply-path efficiency, fraud prevention and privacy compliance.
For enterprise media teams, seller evaluation will increasingly become part of the campaign planning process rather than a technical issue handled solely by AdOps.
Top Insights
- Pixalate’s Q1 2023 indexes rank programmatic sellers across CTV, mobile and web, giving advertisers another framework for evaluating supply-chain quality.
- FreeWheel, Magnite, OpenX, Index Exchange and other major sellers ranked among leading CTV supply partners across Roku, Fire TV and Samsung.
- MobileFuse, IronSource and OpenX led the mobile seller rankings, highlighting differences between in-app advertising supply and traditional web inventory.
- Sharethrough and Sovrn topped Pixalate’s U.S. web rankings, underscoring the continuing importance of seller transparency in mature programmatic markets.
- Seller quality data can support supply-path optimization, helping enterprise advertisers evaluate media partners beyond CPM, reach and audience targeting alone.
Get in touch with our Adtech experts
