The news: WPP has lost the $1.7 billion Mars global media account to Publicis, marking a significant blow just months after Coca-Cola moved its North America account to the rival holding company.

• The deal, which accounts for roughly 1% of WPP’s global revenues, includes media planning and buying across Mars’ global brands, along with production, social, influencer, and connected commerce.
• IPG’s Weber Shandwick will take over PR duties, while creative work remains with Omnicom’s T&P.
• Mars’ shift comes as the brand aims to modernize its “Growth Playbook,” prioritizing integration, personalization, and co-creation across agency partners.

Holdco hostilities: WPP is responding to Publicis with an unusually aggressive tactic, Ad Age notes: an internal “intelligence report” circulated to clients that accuses Publicis-owned supply-side platform Epsilon of delivering low-quality programmatic inventory.

• The report flagged poor viewability (43% overall, just 2% on one CitrusAd-linked site) and high rates of made-for-advertising (MFA) content, suggesting nearly half of impressions in some placements lacked real impact—and that’s a big deal to marketers (see chart).
• Publicis denied the claims, alleging WPP manipulated the results by targeting low-quality buys and disabling brand safety tools. The move has escalated what was once a private rivalry into public confrontation, a rare tactic in the holding company world.

Zooming out: The timing compounds internal challenges for WPP, including CEO Mark Read’s planned exit at year’s end and the oversight of new chairman Philip Jansen.

• The holding group has struggled with shrinking traditional media budgets, competitive pressure from digital-first platforms like Meta, and macroeconomic headwinds.
• The intensity of the dispute reflects a shrinking pool of high-value media accounts, with agency holding companies’ share of US ad spend falling from 44.6% in 2019 to just 29.6% in Q1 2024 per Advertiser Perceptions.

Our take: WPP’s loss of Mars should serve as a wake-up call. The shift from client wins to client warnings suggests a company on the defensive, struggling to keep pace with Publicis’ momentum and the rising consolidation of agency power.

• With Read’s departure looming, internal unrest growing, and the Omnicom-IPG merger looming, WPP’s leadership vacuum and public posturing point to deeper issues.
• If the firm is to regain trust from both clients and investors, its next CEO will need more than spin—they’ll need a reset that focuses on clarity, capability, and client outcomes.