Carbon-Neutral Campaigns That Perform: A GreenPMP Yield Data Breakdown

For years, a quiet friction existed in the advertising industry: the deeply held belief that prioritizing sustainability meant inevitably sacrificing scale or performance. In the boardroom, sustainability was often viewed as a "nice-to-have" checkbox for annual reports rather than a core driver of media efficiency. The assumption was simple—by narrowing the pool of available inventory to only "green" options, advertisers would face higher costs, lower reach, and diminished returns.

However, new data emerging from 2024 and 2025 has officially debunked that myth. Recent large-scale implementations have proven that decarbonizing your media supply chain is not just an ethical mandate; it acts as a powerful quality filter for better financial returns. Far from being a trade-off, sustainable media buying is increasingly recognized as a sophisticated optimization strategy that strips away waste from both the environment and the balance sheet.

In this breakdown, we examine the empirical evidence provided by major agency shifts and meta-analyses from industry leaders like Scope3. The results suggest that the era of "Green vs. Gold" is over. Today, the most efficient path to high performance is the same path that leads to carbon neutrality.

The Quick Verdict: Legacy Programmatic vs. GreenPMPs

For those seeking a high-level summary of how sustainable media stacks up against traditional programmatic buying, here is the state of the industry in 2026:

• Best for Reach at Any Cost: Legacy Programmatic (but with high financial and environmental waste).
• Best for High-Quality Yield & ROI: GreenPMPs.
• Winner for Operational Efficiency: Automated GreenPMPs.

Feature	Legacy Programmatic	GreenPMPs (Automated)
Carbon Footprint	High (Unfiltered)	Low (50%+ Reduction)
Inventory Quality	Mixed (Includes MFA)	High (Verified Low-Emission)
Campaign Scale	Maximum	Full (No negative impact)
Maintenance	Low (Manual)	Hands-off (Dynamic)
Ad Clutter	High	Minimal

1. The "Green vs. Gold" Fallacy: Why Reach Does Not Equal Results

The historical misconception that sustainable media buying limits reach has been the primary barrier to adoption. Marketers feared that by applying a carbon filter, they would lose access to the massive scale required for global campaigns. This "Green vs. Gold" fallacy suggests that there is a binary choice between doing good for the planet and doing what is best for the campaign KPIs.

Data from 2025 has proven this assumption wrong. When brands remove high-emission inventory, they are not removing "quality" reach. Instead, they are removing the bottom-tier inventory that provides little to no real value to the advertiser. This includes sites with excessive ad density, auto-refreshing placements, and "Made for Advertising" (MFA) content that artificially inflates impression counts without driving engagement.

By shifting the focus from raw volume to "efficient reach," advertisers find that their budgets go further. The scale that is lost when switching to GreenPMPs is almost exclusively the "wasteful" scale that was dragging down campaign averages. Consequently, the Gold (ROI) and the Green (Sustainability) are actually found on the same side of the ledger.

2. The Horizon Media Benchmark: Dissecting the 300 Million Impression Test

To understand the practical application of this shift, we must look at the data from Horizon Media’s move to GreenPMPs. Starting in May 2024, Horizon Media, the largest independent media agency in the U.S., transitioned all of its programmatic campaigns through Sharethrough’s GreenPMPs. This was not a small-scale pilot; it was an industry-first test of sustainability at scale.

The results, analyzed in early 2025, were staggering. Across more than 300 million impressions, Horizon Media achieved an average 51% reduction in carbon emissions for display campaigns and a 57% reduction for video campaigns. Critically, the agency reported no negative impact on scale or campaign delivery.

The environmental impact of this single agency shift was significant. The transition avoided 34 metric tons of CO2e, which is the equivalent of driving a gas-powered car from New York City to Los Angeles 31 times. Furthermore, by utilizing GreenPMPs, an additional 88 metric tons of CO2e were measured and fully compensated through carbon-removal projects. This data proves that carbon neutrality is achievable at the highest levels of programmatic spend without compromising a single line item of performance.

3. The Mechanism of Action: Why GreenPMPs Outperform Legacy Supply Paths

To understand why GreenPMPs perform better, we have to look at the correlation between carbon emissions and ad quality. Scope3 research has consistently shown that the highest-emitting publishers are often the lowest-performing for brands. High emissions in digital advertising are frequently caused by technical bloat: heavy page loads, hundreds of simultaneous ad calls, and high-frequency ad refreshing.

These high-carbon sites are the digital equivalent of a high-pollution factory. They are inefficient by design. When a user visits an MFA (Made for Advertising) site, the sheer volume of server-side requests generated to fill a dozen ad slots creates a massive carbon spike. These same environments are also notorious for low attention, high fraud, and poor brand safety.

By using GreenPMPs, advertisers are effectively using carbon as a proxy for quality. By filtering out the top 10% of high-emission inventory, you are simultaneously filtering out the inventory most likely to be ignored by users. This overlap ensures that GreenPMPs don't just reduce carbon; they increase the concentration of high-attention, high-value impressions in your media mix. This is why GreenPMPs often show a lift in click-through rates (CTR) and video completion rates (VCR) compared to unfiltered legacy deals.

4. Automated vs. Manual Decarbonization: The New Standard for Efficiency

As sustainability moves from a niche concern to a standard requirement, the method of decarbonization has become a critical point of comparison. Historically, agencies used manual exclusion lists—static spreadsheets of sites to avoid. However, the programmatic landscape moves too fast for manual maintenance.

Research from Scope3 and the ANA highlights a clear hierarchy of effectiveness in decarbonization solutions:

Manual Inclusion/Exclusion Lists

While a step in the right direction, manual lists are often outdated the moment they are created. They require constant human labor to update and can accidentally lead to "media spend bloat" as too many advertisers compete for a small, static list of high-quality sites. They are a blunt instrument in a world that requires a scalpel.

Automated GreenPMPs

Automated solutions, like Sharethrough’s GreenPMPs, use dynamic data to optimize the supply path in real-time. These tools automatically identify and remove "climate risk" publishers based on live emission data. Because the system is automated, it can adjust to changes in publisher behavior instantly.

Automated solutions also reduce the risk of human error and save significant time for media buyers. More importantly, they allow for a broader, more fluid pool of inventory that maintains the necessary scale for large campaigns while ensuring that every impression meets a specific carbon-efficiency threshold.

Final Verdict: Sustainability is the Ultimate Optimization Metric

The data is conclusive: the friction between performance and sustainability was a phantom of the early programmatic era. In 2026, we now recognize that carbon-heavy inventory is synonymous with wasteful inventory.

Switching to GreenPMPs allows brands to:

• Reduce their campaign carbon footprint by over 50%.
• Improve overall inventory quality by filtering out MFA and high-refresh sites.
• Maintain full campaign scale and reach.
• Automate the path to carbon neutrality without increasing operational overhead.

For advertisers looking to modernize their supply path, the choice is no longer about "sacrificing" for the planet. It is about using the most advanced tools available to ensure that every dollar spent is buying the highest quality media possible.

Start stripping the waste from your supply path. Contact Sharethrough today to learn how you can transition your existing deal IDs to GreenPMPs and begin delivering carbon-neutral campaigns that actually perform.