Could Omnicom–IPG control 50% of global ad spend amid warnings of messy integration?

New Delhi: Omnicom has officially completed its acquisition of Interpublic, forming what it calls the world’s leading marketing and sales company built for “intelligent growth” in the next era.

The merger, cleared after all regulatory approvals, unites Omnicom and Interpublic’s combined revenue of over $25 billion under a single OMC-listed entity, powered by Omni, the group’s advanced intelligence platform.

Chairman and CEO John Wren described the deal as “a defining moment for our industry,” signalling a new standard in how data, creativity and technology will come together for clients.

What looks, at first glance, like a combination of two giant balance sheets is in fact the clearest signal yet that advertising as we know it is rewriting its own rules.

The implications of the Omnicom–Interpublic merger go far beyond the creation of a $25-billion behemoth.

Industry leaders say the deal exposes deeper questions about what scale really means in today’s advertising economy and whether legacy holding groups can reinvent themselves fast enough.

Their views reveal an industry navigating uncomfortable truths about consolidation, capability gaps, cultural integration and the accelerating shift toward data-driven marketing.

The big five

In many ways, the Omnicom acquisition of IPG feels like the closing arc of a story that has been unfolding for over a decade.

Ashish Bhasin, founder of The Bhasin Consulting Group and former Chairman and CEO, APAC, Dentsu, sees it as the point where a long-running consolidation cycle finally hits its peak.

He described consolidation as a powerful undercurrent running through every part of the media and marketing ecosystem and noted how smaller agencies have been absorbed for years. The only difference now is that the wave has reached the holding companies themselves.

As he put it, “Consolidation is a very strong trend in advertising, not just at the agency level but also among broadcasters, publishers, and across the ecosystem. It has been a global trend for several years.”

He believes the end outcome will not be a diversified landscape but a narrower one where a handful of giants dominate global decision-making.

“We will probably end up with two very strong players at the top, Omnicom and IPG (or whatever the merged entity is eventually called). Then there is Publicis. Next would be WPP, which was once the clear number one but has been losing ground. And after that, Dentsu and Havas. These five will likely control around 80% of the market globally.”

Adding context to the global market dynamics, Angel Investor and Business Strategist Lloyd Mathias noted that the merger strengthens the new entity’s presence across the US, Europe, Asia, and emerging markets.

“Publicis is strong but Europe-heavy. WPP is pan-global but historically UK- and Europe-centric. In that sense, this consolidation tilts the balance toward the Omnicom-IPG entity,” he said

On a hypothetical market-share split of 50:30:20 between Omnicom-IPG, WPP, and Publicis, Mathias estimated, “I’d say upper 40s for the merged entity, with the other two splitting the remaining share.

Shivaji Das Gupta, an autonomous Brand Consultant, described the larger shift with a wider lens. To him, such consolidation triggers impact across five layers that stretch from people to competitive dynamics. 

He breaks it down clearly.

“The first is the human impact, as employees face apprehensions about career continuity, stability, and the future structure. The second is the impact on clients: they will benefit from better efficiencies and fewer duplications, and will the service model become more seamless?

Third comes the business impact, influencing top lines, bottom lines, and profitability. Fourth is readiness for emerging technologies like AI, asking whether the combined entity can handle AI better, both internally and as a client solution. Finally, there is the competitive impact: will this create a deeply differentiated product, and could it trigger further consolidation among rival groups?”

Das Gupta’s framing sets the tone for how the Omnicom-IPG merger will be interpreted across boardrooms and creative floors alike.

Every decision, from talent allocation to client servicing and technology investment, will reverberate through these five interconnected layers. Leaders will wrestle with managing people and aligning cultures while navigating client expectations, business performance, technological readiness, and competitive positioning.

The cultural collision

While the financials behind the deal have dominated headlines, industry veterans are unanimous that the real test lies elsewhere. Every merger promises synergy on spreadsheets, but synergy in a people-driven business is far harder to engineer.

Bhasin captured this tension succinctly, saying, “In any acquisition, the biggest challenge is not the financials. Those get handled by accountants, lawyers, and consultants. The real challenge is managing stakeholders, employees and clients.”

It is a reminder that the advertising industry trades in ideas, craft and relationships, not just numbers. Integration often runs into invisible but entrenched walls of legacy, pride and uneven leadership alignment.

Or, as Bhasin described it, things appear deceptively manageable on Excel sheets but play out very differently on the ground.

Alok Lall, former Executive Director, McCann Worldgroup, noted the silence within both companies and called it dangerous for a sector built on talent retention. "Inside IPG, there is a lot of uncertainty because the management has not spoken clearly. The same goes for Omnicom. This industry runs on talent. If you have the talent, you have the business. If you lose the talent, you lose the business. So uncertainty is dangerous."

His reflections on past integration efforts are equally telling. “Many holding companies have not done consolidation well. Havas and Publicis have been reasonably successful, but WPP, IPG, Omnicom and Dentsu have all struggled. Dentsu tried and could not make it work.”

Even guided integration is not guaranteed, as he learned firsthand. “When I joined McCann, integration was the buzzword. My job was to integrate all offerings. Even with integration experience, I struggled. Territories, egos and legacy structures make integration tough.”

Dasgupta drew from his own years inside WPP to illustrate why promised synergies rarely reach the service layer. Senior leadership may experience alignment, but teams working with clients seldom feel the change in any meaningful way, which is why he sees the benefits of such mergers as largely financial manoeuvres rather than improvements in the product itself.

The core challenge, therefore, is not the scale of the merger but the human friction that scale magnifies.

India’s position in the new hierarchy

From afar, mergers of this size look like they will trigger immediate disruption across markets. In India, though, the immediate effect will be far more contained.

Mathias grounded the conversation with pragmatic clarity and argued that the short-term impact on brands will be minimal. “In the immediate term, and likely for the next year, nothing will change significantly for brands and businesses. Network consolidation is not new. Clients already work with competing agencies under the same network.”

The bigger changes, he explained, will unfold behind the scenes in support functions that can be merged without risking client relationships. Centralisation of intelligence, HR, research and procurement will be natural first steps because they create efficiency without destabilising front-end teams.

Media, however, is expected to undergo more profound restructuring. Mathias suggested that networks like Lodestar, Interactive Avenues and Rapport could be consolidated under fewer decision makers because media is where cost synergies and negotiating power scale most quickly.

This is also where India’s competitive landscape could shift. Lal quantified it sharply by comparing the buying clout. “GroupM is roughly about Rs 6000 crore. IPG is around Rs 2000 crore. Publicis and others are around Rs 1000 crore. With Omnicom plus IPG, their total business in India may inch close to roughly Rs 3000 crore. GroupM will still be number one, but the merged entity will be a strong number two.”

For media owners, that means tougher negotiations. For brands, it might result in more competitive rates in the short run.

But the merger does not solve a structural problem that agencies continue to battle.

Mathias cautioned that traditional networks remain slow for digital-first brands, which explains why hotshops and independents continue to win modern mandates. Scale does not automatically translate into agility.

The future of agency brands

One of the more emotional aspects of consolidation is the loss of iconic agency names. Global advertising has watched some of its most storied brands fade or be folded into larger structures.

Bhasin believes this merger will further shrink the list of active agency marques. He sees the writing on the wall. “In most consolidations, agency brands become casualties. Iconic brands have disappeared over the years. Both Omnicom and IPG have their own creative agencies. It may not be feasible or necessary to keep all of them.”

Das Gupta emphasised that even when the logic for keeping brands alive exists, the internal politics of P&Ls can override it.

Mathias forecasted that of the major creative brands operating in India, one or two will likely merge in the coming years. He identifies four strong contenders for survival and a probable candidate for absorption, stating that TBWA is currently the weakest and therefore most vulnerable.

“To me, the four strongest creative agency brands that will remain independent are McCann (with strong leadership under Prasoon Joshi), Lowe Lintas (despite recent struggles), DDB Mudra (very powerful in India) and BBDO (which has grown substantially in the past five years). FCB might also remain independent because of large clients like Tata and Marico. But TBWA, which is currently the weakest, is the most likely candidate for consolidation,” Mathias said.

This process is rarely dramatic and usually unfolds quietly but steadily in the form of merged leadership, reduced P&Ls or shared back ends. For employees, the implications can be significant even when the changes are not publicly announced.

What clients will actually feel

Marketers often worry that mergers will disrupt service quality or force them into conflict-ridden relationships. However, industry experts dismissed such fears in the short term. Das Gupta made the point most succinctly when he said, “Clients do not care about the merger. They care about outcomes.”

The real challenge, however, lies in category conflicts that are inevitable at a global level. Bhasin points out that categories like beverages or automotive often have fierce competitors housed under different agency networks.

Bringing them under one umbrella introduces tensions that cannot be resolved instantly. “Clients will also face conflict situations. For example, if one agency handles Coke and the other handles Pepsi. Both companies will have clients across every major category. Managing these conflicts, along with people, is the hardest part.”

Even then, the experts agree that Indian marketers are unlikely to feel major disruptions soon. A client working with BBDO or Lowe Lintas will continue to work with them until global structures mandate otherwise, and that typically takes years.

The long-term picture, though, is less predictable. As networks consolidate and P&Ls merge, client teams may begin sharing common back ends or leadership, increasing the possibility of blurred boundaries.

The real driver: AI and tech capability

Beyond scale and buying muscle, the most strategically urgent reason for this merger lies in the rising cost of building AI models, data systems and content automation frameworks. Das Gupta identified this as one of the key pillars of consolidation impact and sees the combined entity as better positioned to invest in future-ready capabilities.

Mathias echoed this, stating that consolidation gives networks the breathing room to save costs for a year, impress Wall Street and funnel capital into AI, data, martech and production technologies.

These investments are no longer optional for networks that want to remain globally competitive. Creative automation, predictive media planning and content factories require capital at a scale far beyond what legacy structures were built for.

In that sense, the merger is not just about beating competitors but about preparing for a future where technology will fundamentally reshape the role of agencies.

What the merger ultimately signals

The Omnicom-IPG merger reshapes the global advertising business in ways that go far beyond procurement efficiencies or stock market reactions. It pushes the industry into a more concentrated era, strengthens the second-largest global network, expands buying clout in key markets like India and creates new financial headroom for investment in AI and data.

Yet the risks remain substantial. Cultural clashes, uncertain talent, disappearing agency brands and inevitable client conflicts could slow the very transformation the merger aims to accelerate.

Lal captured the cultural asymmetry bluntly when he said, "Someone has bought you. The buyer gets the head seat on the board. IPG may not even have a board seat. In a sense, IPG will cease to exist, and the acquirer’s culture will dominate."

Advertising is a business where creativity and culture are as critical as balance sheets. The success of the new entity will depend not only on its scale but also on whether it can preserve the talent and creative energy that give it purpose.

For now, the merger brings the industry into a new chapter. The consolidation cycle may be peaking, but the cultural cycle is only beginning.