Supply path optimisation becomes a core strategy for improving programmatic ad quality

Supply path optimisation has become one of those terms the advertising industry returns to whenever fraud, made-for-advertising inventory or brand safety problems flare up. The concern is familiar; the discipline, less so. For many organisations, SPO is still treated as an occasional clean-up exercise rather than a standing commercial priority, even though the value at stake is increasingly hard to ignore.

The case for a more rigorous approach is built on waste. Programmatic bu...

ying often involves a long chain of intermediaries before an impression reaches a publisher, and every extra hop can add fees, slow delivery and create another opening for low-quality inventory or invalid traffic to creep in. Industry analysis has long suggested that this complexity carries a substantial cost, with one estimate putting annual losses from supply-chain inefficiency at $21.6bn.

The latest benchmarking discussed by the Association of National Advertisers suggests the market is making progress, but unevenly. A recent ANA transparency benchmark reported that 99.1% of impressions were running in low-risk environments, while working media efficiency across web, mobile and connected TV improved from 36% in 2023 to 47.1% in the third quarter of 2025. That gain translated into $13.6bn in recovered value, aided by lower SSP fees, less exposure to made-for-advertising sites and more disciplined path selection.

That improvement does not mean the problem has gone away. Human Security, citing the ANA’s first-quarter 2025 benchmark, said only 41% of programmatic spend was translating into quality impressions, leaving nearly 60% tied up in non-quality inventory. The same analysis said more than a third of open-programmatic spend still goes to waste on low-quality or fake impressions, underscoring how much room remains for tighter control of the buy-side supply chain.

The strongest advertisers are increasingly treating SPO not as a way to chase the cheapest cost per thousand, but as a lever for business performance. That distinction matters. Buying the lowest-priced path can shift spend towards poorer inventory and weaker outcomes, while a cleaner path may cost more per impression but deliver better viewability, stronger measurement, less fraud exposure and healthier return on ad spend.

Recent performance data supports that view. According to the material cited by Basis, advertisers that maintained rigorous quality governance in the fourth quarter of 2025 directed 56.7% of programmatic spend into impressions that were viewable, measurable and free of fraud and MFA risk, compared with 37.5% for lower-performing advertisers. The same dataset said cost per conversion fell by nearly 40% for advertisers optimising for quality, even as CPMs rose.

The structural shift in the market is also visible in the decline of made-for-advertising inventory. The Current reported that what had been a meaningful leakage point in 2023 had collapsed to about 0.4% of programmatic spend by 2025, a sign that cleaner supply paths are becoming a competitive differentiator for major SSPs rather than just a brand-safety talking point. That does not eliminate risk, but it suggests that stronger governance can quickly change where money flows.

There is still a gap between buyer and seller priorities. AdMonsters reported that only 30% of publishers regard SPO as important, a reminder that many publishers see the issue largely as a demand-side concern while focusing on broader pressures such as the economy, attention metrics and cookie deprecation. That divide helps explain why SPO remains difficult to sustain as a shared industry discipline.

For advertisers, the practical test is whether a platform can answer hard questions about transparency. Buyers should be able to see hop counts, SSP take rates, publisher-level pricing, data and identity sources, brand safety controls and the differences between deal types. In retail media, where conflicts of interest can be more pronounced, that visibility becomes even more important. If a platform cannot explain the route clearly, it is probably not mature enough to manage it well.

The wider context makes the need for that scrutiny even clearer. AI Digital noted that IAB Europe found 87% of brands, agencies and DSPs were already implementing SPO strategies, driven by brand safety, fraud reduction and better key performance indicators. Forbes has likewise argued that SPO is becoming central to accountable programmatic buying as transparency demands rise and the identity landscape becomes more fragmented.

The industry’s broader lesson is simple. SPO is no longer just a reaction to the latest fraud scare or transparency report. It is a permanent management task, and the advertisers that treat it that way are better placed to protect media value, improve performance and build a more resilient supply chain.

Source: Noah Wire Services