WPP targets Epsilon over programmatic ad quality; Publicis hits back

New Delhi: In a rare public confrontation between global ad giants, WPP has accused rival Publicis Groupe of flooding the programmatic ecosystem with low-quality inventory via its Epsilon SSP. 

The charge is detailed in an 8-page audit titled the Epsilon Intelligence Report, released by WPP Media on June 9, marking an unusual escalation in what is typically a behind-the-scenes rivalry.

The audit, conducted over two days in May 2025, involved a controlled programmatic buy using a global DSP. 

WPP bought ad placements exclusively from direct publishers on Epsilon’s exchange, deliberately excluding resellers. Performance was benchmarked against third-party platforms, including Adelaide and Jounce.

Key findings from WPP’s report:

• Ads were purchased across 503 domains and apps on Epsilon SSP.
  
  
• Average viewability was 43%, with some properties as low as 1–2%, well below the ANA benchmark of 64.8%.
  
  
• 26% of impressions were flagged as Made-for-Advertising (MFA) content by independent third parties.
  
  
• Attention scores were over 40% lower than the Q1 2025 industry benchmark from Adelaide.
  
  
• Over 900 sellers were listed as both publishers and sellers, raising concerns about transparency and traceability.
  
  
• Some domains were classified by WPP’s partners as clickbait or IP-infringing.
  
  

A standout slide in the report claimed, “The intelligence report unveiled Publicis-owned supply that was MFA or clickbait at worst and low-quality, low-attention at best.”

WPP further alleged that “Epsilon (owned by Publicis) has made the decision to onboard these publishers directly onto their platform and is now commercially incentivised to sell MFA, clickbait, and chronically non-viewable inventory to their clients and the wider market.”

Third-party firms conducted all analyses of viewability, attention, and domain classification.

Why WPP went public

According to the report, WPP Media regularly conducts such supply chain assessments. However, it chose to publish this one “to warn clients and the wider market.”

“We are increasingly seeing programmatically available inventory from competitors being resold via global SSPs. Wherever we find such inventory being surfaced, we block it to ensure client safety,” the report noted.

WPP argues that Publicis has made a “strategic decision” to monetise MFA supply not only through its own SSP but also by redistributing it via other platforms, thereby amplifying the risk.

What Publicis has to say

In an Ad Age story, a Publicis spokesperson said, “We don’t normally respond to [WPP’s] desperate moves, as it doesn’t help our industry. But in the face of such obvious falsehoods, we can’t stay silent.”

The statement read, “WPP continues to claim innovation, this time by inventing their own ‘audits’ of their competitors. They’re doing it in a domain where they’ve recently excelled—throwing mud at their peers rather than focusing on their clients and their people.”

Publicis then went out to highlight in the Ad Age story that GroupM attempted something similarly underhanded last summer. It’s part of a growing pattern of behavior from them that lacks integrity and is a sad reflection on how far a once formidable player has fallen. But even more importantly, it’s a disservice to the industry as a whole and grossly underestimates the intelligence of clients.”

“WPP has fabricated a narrative by intentionally and actively disabling industry-standard inventory controls and brand safety technology in order to generate highly misleading ‘results,’” the statement said.

It further wrote, “We have identified their exact buy, which is less than $200 and carries a CPM of 46 cents. After vigorous testing on our part, we have found that in order to produce these fake results, WPP would have had to disable all protections for made for advertising (MFA) and site exclusion lists in the platform; purposefully avoid using a brand safety provider; actively target low-cost impressions; deliberately remove the viewability floor; and sabotage ‘attention’ performance as measured by [attention measurement company] Adelaide by limiting the ‘audit’ to only a single creative size."

A strategic power play

This battle goes beyond inventory quality. It is part of a broader power struggle in the global advertising landscape. Publicis, which recently overtook WPP in global revenues, has been on a high with acquisitions like Epsilon and Sapient and the rollout of its CoreAI platform.

For WPP, which is undergoing leadership transition with CEO Mark Read set to retire this year, the move may be aimed at restoring client confidence, particularly in programmatic and retail media environments where ad quality is under scrutiny.

Industry implications

WPP’s forensic disclosure may mark a turning point for how ad holding groups disclose and manage SSP supply quality. Agencies, trading desks, and procurement heads are now expected to demand greater third-party validation of supply chains. Other holding companies could also come under pressure to disclose their audit protocols.

“WPP’s decision to publish this audit forces the industry to confront uncomfortable truths about scale versus quality. It’s no longer just a matter for pitch decks—it’s now a public conversation,” said a senior media executive on condition of anonymity.

Having said that, Ad Age cited several consultants who questioned the report’s reliability and transparency. “I wonder at what level in the organisation this was sanctioned, as there are no names or details of any author in the report,” said Ebiquity’s Schreurs. “Details on methodology are also too limited to judge the validity of their claims.”

Another marketing consultant emphasised that such analyses typically require an independent third party for objectivity. They highlighted the report’s vague targeting details and its short evaluation window—only two days in May.