With 2026 just days away, take a look at the major stories of 2025 - and their impact across the ad tech landscape…

Mergers old and new reshaped the agency landscape; regulators pushed back against the giants; and Google quietly admitted something few thought possible - that the cookie era might be here to stay after all.

Omnicom and IPG: The year’s defining merger

Last December’s news that Omnicom would acquire IPG sent shockwaves through Madison Avenue. The deal, worth an estimated USD$25bn, promised to create the world’s largest agency network - a marketing behemoth with combined billings dwarfing even WPP’s. Unsurprisingly, the US Federal Trade Commission (FTC) stepped in, flagging concerns that the tie-up could limit competition across media buying, creative services, and data management.

For months, the transaction hovered in limbo. But a revised framework for “cross-stack ad competition” introduced midyear gave the merger new life. By late summer, the FTC cleared the deal, followed in December by unconditional approval from the European Commission. Almost immediately, Omnicom announced a sweeping restructure: 4,000 roles set to go before year-end as it moves to consolidate overlapping units and unify its data strategy under a single global platform.

Consolidation everywhere you look

The mergers kept coming. French-based Equativ sealed its long-discussed union with Sharethrough, forming one of the largest independent ad tech platforms outside the walled gardens. The combined group now boasts significant reach across CTV, programmatic, and supply optimisation.

Meanwhile, Publicis made headlines with its acquisition of Lotame. The move adds Lotame’s data reservoir - roughly 1.6 billion user profiles - to the Groupe’s increasingly ID-driven data stack. Publicis wasted no time folding those audience graphs into its Epsilon offering, pitching enhanced precision targeting just as fragmentation across identifiers reached new highs.

The battle for Warner Bros

In media, the year’s most extraordinary rumour mill centred on Warner Bros Discovery, which officially put itself up for sale. Both Netflix and Paramount Skydance made plays - and Netflix seemed to have the agreement in place. Paramount then lobbed in a USD$108.4bn hostile bid, aiming to outmuscle Netflix’s already massive USD$72bn offer. The board, though, recommended rejecting Paramount’s offer - but few expect this story to end before 2026.

TikTok survives again - with a new flag

Across the Atlantic, political drama continued to define TikTok’s fate. In September, a newly re-elected Donald Trump signed an executive order forcing Chinese parent company ByteDance to transfer US ownership to American investors. The move, framed as a national security measure, effectively prevented a TikTok shutdown in the States - and marked the culmination of a years-long tug of war over the app’s future.

ByteDance eventually reached a binding deal with groups including Oracle, Silver Lake, and MGX. If completed in early 2026, the agreement will create a separate joint venture for TikTok’s US business, finally putting the app’s legal limbo to rest - at least for now.

Google’s rough year in court

No year-in-review would be complete without Google’s legal woes, and 2025 delivered them in spades. The search giant faced a crushing verdict in April, when Judge Leonie Brinkema ruled that it maintained two illegal monopolies across ad tech - one in publisher ad servers, another in exchange technology. 

The decision unleashed fresh lawsuits from Magnite and PubMatic, both seeking damages for what they describe as years of exclusionary practices.

Yet the more draconian remedies - a forced breakup or Chrome divestiture - seem increasingly unlikely. Judge Amit Mehta spared the browser from sale in Google’s parallel search antitrust trial, and Brinkema has signalled similar hesitation in the ad tech case. Pending verdicts aside, the industry’s response has been pragmatic: frustration, but little shock. The perceived imbalance between regulators’ power and Big Tech’s legal muscle remains, for now, intact.

AI upends traffic and trust

While courts debated competition, the open web faced a different kind of existential challenge. As AI chatbots and search tools proliferated, referral traffic to publishers cratered. Appfigures and SimilarWeb both recorded steep double-digit declines in click-throughs to news sites across major markets, with much of that traffic diverted to AI-generated summaries.

Publishers responded with lawsuits, block lists, and pleas for licensing deals. Yet the scraping continued and 2025 became, by consensus, the year that open access content was effectively subsumed into large language model training data. One board member of the Independent Publishers Alliance estimated that Google’s new AI-powered search could push a third of its members into closure within a year.

What AI giveth in efficiency, it taketh away in discoverability.

The cookie that wouldn’t crumble

And finally, the year’s most unexpected twist: the third-party cookie lived to see another day. After half a decade of phased plans, pilot schemes, and developer summits, Google officially scrapped its deprecation timeline. Privacy Sandbox was quietly wound down, its core tools shuttered.

The decision, reportedly tied to both antitrust pressure and publisher backlash, sent shockwaves across the ecosystem. After years spent preparing for a “post-cookie world”, advertisers and platforms alike found themselves back where they started - albeit older, wiser, and more cynical about Google’s willingness to change its own rules.

For some, that retreat marked the end of an era. For others, it was a fitting conclusion to a year defined by circular upheaval: consolidation without clarity, innovation without confidence, and regulation without resolve.

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