In a highly unusual and direct confrontation, global advertising behemoth WPP has launched a scathing attack on rival Publicis Groupe, alleging that its Epsilon supply-side platform (SSP) is deliberately pushing “low-quality” ad inventory into the programmatic ecosystem. The accusations are detailed in an eight-page “Epsilon Intelligence Report” disseminated directly to WPP’s clients by WPP Media on June 9, marking a rare public escalation in the intensely competitive ad industry.
The report, a result of a two-day controlled programmatic buy conducted in May 2025, claims that Publicis-owned Epsilon has “made the decision to onboard these publishers directly onto their platform and is now commercially incentivised to sell MFA [made-for-advertising], clickbait, and chronically non-viewable inventory.” WPP’s audit outlined several concerning findings, challenging the quality and transparency of Epsilon’s ad placements:
- Dismal Viewability: Ads purchased across 503 domains and apps on Epsilon SSP showed an average viewability of just 43%. Alarmingly, some properties dipped as low as 1-2%, falling significantly below the Association of National Advertisers (ANA) benchmark of 64.8%.
- Prevalence of MFA Content: A substantial 26% of impressions were flagged as “made-for-advertising” (MFA) content by independent third-party evaluators. MFA sites are typically designed to maximize ad displays with low-value or AI-generated content, often characterized by dense layouts and rapid ad refreshes for cheap CPMs.
- Poor Attention Scores: The report indicated that attention scores for Epsilon’s inventory were over 40% lower than the Q1 2025 industry benchmark from Adelaide, a third-party platform specializing in attention measurement.
- Transparency Concerns: Over 900 sellers were listed as both publishers and sellers within Epsilon’s platform, raising significant questions about transparency and traceability in the supply chain.
- Questionable Domain Content: Certain domains were explicitly labeled as clickbait or IP-infringing by WPP’s verification partners.
A prominent slide in the “Epsilon Intelligence Report” bluntly stated: “The intelligence report unveiled Publicis-owned supply that was MFA or clickbait at worst, and low-quality, low-attention at best.” WPP emphasized that all analyses of viewability, attention, and domain classification were conducted by independent third-party firms, including Adelaide and Jounce.
While WPP Media regularly conducts such supply chain assessments, the decision to publish this specific report was made “to warn clients and the wider market.” The company added that it is “increasingly seeing programmatically available inventory from competitors being resold via global SSPs” and that “wherever we find such inventory being surfaced, we block it to ensure client safety.” WPP further asserted that Publicis has made a “strategic decision” to monetize MFA supply not only through its own SSP but also by redistributing it via other platforms, thereby escalating the risk for advertisers.
This public spat underscores deepening cracks in the media supply chain, as brands demand greater transparency and quality in programmatic advertising. The clash also comes amid fierce competition for data-driven growth and client retention between the two ad giants. Publicis, which recently surpassed WPP in global revenues, has gained momentum through acquisitions like Epsilon and Sapient and the launch of its CoreAI platform. For WPP, currently navigating a leadership transition with CEO Mark Read’s impending retirement, this move could be an attempt to restore client confidence, particularly in programmatic and retail media, where ad quality is under increasing scrutiny.
Industry observers anticipate that this direct challenge could have significant implications for the advertising industry, likely leading to increased demand for third-party validation of supply chains from agencies, trading desks, and procurement heads. Other holding companies may also face pressure to disclose their audit protocols and ensure the quality of their programmatic inventory.
Key Highlights:
- WPP has publicly accused rival Publicis Groupe’s Epsilon platform of distributing “low-quality,” “made-for-advertising” (MFA), and “clickbait” ad inventory in a client-facing “Epsilon Intelligence Report.”
- The report, based on a May 2025 programmatic buy, cited low viewability (43% average vs. ANA’s 64.8% benchmark), 26% MFA impressions, and 40% lower attention scores as key findings.
- WPP alleges that Publicis is “commercially incentivised” to sell this subpar inventory and is actively redistributing it across the broader programmatic ecosystem.
- This rare public dispute highlights rising industry concerns over ad quality and transparency, intensifying the rivalry between the two advertising giants for market dominance and client trust.