The Rise of the Marketing Consigliere: How Mediasense and Peers Are Navigating the 2026 "Mediapalooza"

The advertising industry is currently caught in the throes of a tectonic shift. As the first half of 2026 concludes, the volume of high-stakes agency account reviews—often dubbed "mediapaloozas"—has reached a fever pitch. With major global players like Coca-Cola in the midst of massive re-evaluations and Intuit recently placing its $1 billion account under the microscope, the intermediary market has become the most vital, yet often overlooked, corner of the marketing ecosystem.

At the center of this transformation are the media consultancies—firms like Mediasense, Ebiquity, ID Comms, and Flock Associates. These entities act as the "consiglieres" to global CMOs, orchestrating the complex, high-risk reviews that determine which agencies will steward billions of dollars in advertising spend. As the industry faces unprecedented levels of complexity, these consultancies are finding themselves in the driver’s seat, tasked with guiding the world’s largest brands through a landscape of diminishing transparency and rising digital risks.

The Winds of Change: A New Era for Mediasense

London-based Mediasense, a titan in this space, is currently navigating its own period of internal evolution. Under the leadership of newly appointed CEO Sam Tomlinson—who ascended from his role as chief client officer last week—the firm is positioning itself to capitalize on the massive wave of reviews expected in the second half of 2026.

Tomlinson takes the helm at a critical juncture. The firm’s majority owner, the U.K.-based private equity firm Apiary Capital, is hitting the five-year mark since its initial investment. In the world of private equity, five years is typically the horizon for an exit or a strategic pivot. Industry analysts suggest that Tomlinson’s mandate is clear: scale the business, streamline operations, and maximize the consultancy’s value proposition to ensure a favorable outcome for its backers.

Tomlinson’s appointment follows the departure of Jamie Posnanski, who has returned to the United States. Having joined Mediasense during its 2024 acquisition of PwC’s U.K. marketing and media assets, Tomlinson brings a pedigree of rigorous financial and operational oversight that he intends to apply to the creative and media agency selection process.

The Strategic Thesis: Independence vs. Expertise

The central pitch of modern consultancies is simple, yet profound: independence. As Tomlinson articulated in an interview with Digiday, the role of the consultancy is to fill a gap in the C-suite’s advisory portfolio.

"Our vision is to be the No. 1 advisor of choice for marketers and their colleagues," Tomlinson explained. "Our thesis is, if you’re a CEO and you want advice, you turn to McKinsey or Bain or BCG. If you’re a CFO, you turn to PwC or KPMG. If you’re a CTO, you turn to IBM or Capgemini. But if you’re a CMO and you want independent expert advice, you can get it from agencies or big tech partners, but that advice is not independent. We want to be the people who provide advice that is both expert and independent."

This positioning is a direct challenge to the traditional agency model, where media planning and buying advice have historically been bundled with execution. As brands grow weary of the lack of transparency in digital media supply chains, the demand for an "honest broker" has spiked.

Chronology of the 2026 Media Review Wave

The current climate of review activity is not an isolated phenomenon but the culmination of several years of market consolidation and frustration.

• 2024: The industry sees a wave of consolidation, marked by Mediasense’s acquisition of PwC’s media assets, signaling a shift toward more technical, data-driven consultancy models.
• Early 2026: Media moves totaling approximately $13 billion in spend are finalized, setting a record pace for the year.
• Mid-2026: A secondary surge of activity begins. At least 27 of the world’s top 100 global advertisers have now gone seven years without a review, creating a "ticking clock" effect that forces them into the market.
• Present Day: Intuit’s $1 billion account moves to review, signaling that even dominant players are looking to recalibrate their agency relationships in light of new AI-driven marketing technologies.

Supporting Data: The Complexity Crisis

The necessity for these consultancies is underscored by a sobering reality: marketers are overwhelmed by data but starved for actionable insight. According to a recent survey conducted by Ebiquity and the World Federation of Advertisers (WFA), which polled 71 marketers representing $40 billion in ad spend, there is a massive disconnect between data collection and decision-making.

While 80% of surveyed advertisers now utilize advanced marketing mix modeling (MMM) and brand lift studies, a staggering 85% admit that these effectiveness metrics are not the primary driver of their budget decisions. This gap between the "data we have" and the "decisions we make" is precisely where firms like Mediasense and Ebiquity claim to add value. They are no longer just pitch managers; they are transformation consultants who help brands build the infrastructure required to actually use the data they collect.

"Our business model is transformation when it leads to growth," noted Ebiquity CEO Ruben Schreurs. "We help clients transform and grow, and that includes everything from McKinsey-level strategy consulting, operating model design, and partner selection to implementation support."

Official Perspectives: The View from the Top

The rivalry between these consultancies is intensifying as they compete for the same pool of senior talent. The "war for talent" is a constant theme, as firms look for experts who can navigate the technical, political, and cultural nuances of global marketing departments.

When asked about the potential for burnout or the "stretching thin" of resources during this period of high demand, Tomlinson emphasized the strength of his existing team. He pointed to the firm’s roster of senior talent, including Greg Paull, Shufen Goh, and Ryan Kangisser, as the backbone of their operations. "We are a growing business," Tomlinson said. "We will continue to hire. Our team is very, very capable of handling senior clients."

For his part, Ryan Kangisser, chief strategy officer at Mediasense, offers a broader philosophical take on the industry’s trajectory. "If 2021 was about efficiency and simplification, 2024 was about recalibration," he noted. "2027 will be far more transformative. Marketers don’t just want another media agency; they want an engine for growth."

Implications: The Future of the CMO-Consultancy Relationship

The shift toward specialized, independent advisory services has profound implications for the advertising industry:

1. The Decline of the "AOR" Model: As consultancies help brands unbundle their services, the traditional "Agency of Record" (AOR) model is likely to further fracture. Brands are increasingly moving toward modular rosters that prioritize best-in-class specialists over one-stop-shop conglomerates.
2. Governance as a Competitive Advantage: With marketing budgets under constant scrutiny from CFOs, the ability to provide "good governance"—a term used by industry leaders to describe transparency, accountability, and ethical media buying—has become a top priority for CMOs.
3. The Rise of the "Consultant-Agency" Hybrid: As agencies attempt to defend their turf, they are increasingly adopting the language and the service models of consultancies, offering "strategic consulting" alongside creative and media execution. This will likely lead to further blurring of the lines between agency and advisor.
4. Heightened Scrutiny on ROI: The era of "brand awareness at any cost" is fading. Consultancies are pushing for higher accountability, forcing agencies to prove the efficacy of every dollar spent, which will inevitably lead to more frequent, data-driven reviews.

Conclusion

As the media landscape grows more complex, less transparent, and increasingly risky, the role of the independent advisor has never been more vital. Mediasense and its rivals are not merely facilitators of pitch processes; they are architects of the modern marketing department.

For CEOs and CMOs, the challenge of the next eighteen months will be to move beyond the reflexive nature of the "mediapalooza" and instead focus on long-term structural transformation. As Sam Tomlinson and his peers look toward the second half of 2026, the firms that succeed will be those that can successfully walk marketers through the technical, political, and existential shifts currently being foisted upon the discipline. In the end, the most successful consultancies will be those that make themselves indispensable, not just as managers of the pitch, but as the architects of the future.