Media Buying Briefing: What Dentsu’s synthetic audiences deal reveals about future of media planning

The less flashy, but more important shift is how AI is being used to gain competitive and operational advantages through applications that alter how decisions are made, how media is allocated and how campaigns perform. 

Take media planning. Today, large parts of the job sit between a marketer’s budget and the media owners who eventually get it. It’s a function built on relationships, reputation and institutional knowledge. Those qualities still matter, but AI is increasingly capable of replicating — or at least supplementing — them.

One example is the so-far nascent use of synthetic audiences for market research, creative testing and increasingly media planning and targeting (the practice is also sometimes called “digital twinning”). To recap, this is the practice of employing a composite audience profile, created by generative AI using several data sources, to target media. 

Japanese holding company Dentsu inked a commercial partnership (the terms haven’t been disclosed) with start-up Evidenza last week, a move that heralds the more widespread use of synthetic audiences.

“We’re taking a really strong, assertive step in how our brands and our clients are able to move from insight to activation,” said Paul Kang, head of alternative investments at Dentsu, who spoke to Digiday from Cannes.

The data they’re based on is real — in Dentsu’s case, the company plans to draw on its own Consumer Connection System (CCS) research panel, as well as data provided by Evidenza — but the profiles created from it are artificial. The personas don’t rely on any personal information and are essentially created whole cloth from probabilistic data sources — hence the “synthetic” moniker.

The Evidenza deal wasn’t the only alliance unveiled by Dentsu this month. It also struck up partnerships with MiQ to use the ad tech firm’s Sigma programmatic platform, and with Criteo to use its Commerce Media Platform tech stack. The moves illustrate a different approach to tech credentials than that taken by its holdco rivals; rather than race to acquire, it’s prioritizing partnership with other marketing industry players.

Though Kang didn’t rule out future M&A activity in this space from the holdco, he suggested that agency businesses shouldn’t be in too much of a rush to slam cash offers down for companies with radically different business models to their own. “We have to be really, really careful in how we make the assertive steps to bring [AI] technologies in-house… you can’t necessarily just go ahead and just acquire a business, because there is inherent risk in doing that, particularly for agencies,” he said.

According to Kang, the partnership will help Dentsu move synthetic audiences on from being a “nascent play” to a technique any of its media planners are able to deploy; he declined to share which client teams were already using the method.

Because AI tools can create such profiles faster than traditional methods relying on survey panels, there’s advantages of speed and cost embedded to be had. According to a statement from Shirli Zelcer, chief data and technology officer at Dentsu, the technique has delivered “greater precision, speed, and agility in planning and activation.”

She said early tests had shown an 87% correlation between AI-generated and traditionally produced audience profiles, “proving we can match the rigor of legacy methods while accelerating time to value and unlocking new growth opportunities.”

It’s also an application of AI tech that, if it becomes commonplace, will inevitably change the work of media planning by leading staffers to rely more heavily on their data, rather than their intuition.

Color by numbers

Following recent forecast downgrades from IPG and WPP Media (mostly in light of U.S. tariff policies), Dentsu’s also released its regular six-month ad spend forecast. The report suggests that global ad spend is forecast to grow by 4.9% in 2025 to reach $992 billion.

• Digital ad spend will account for 68.4% of that, growing 7.9%. 
  
• Though the U.K. leads ad spend growth in Europe, Africa and the Middle East (with 6.9% ad spend growth versus a 4.5% average), investment in the Americas lags, with growth at 4.2%.
  
• Retail media spend is forecast to grow by 13.9% in 2025 and social 9.2%.

Takeoff & landing

• There’s been more executive shakeups at IPG Mediabrands. Stacy DeRiso has succeeded Dimitri Maex as the president of Initiative. M+C Saatchi Group appointed Jackie Stevenson (formerly EMEA chief growth officer at IPG) as its global chief strategy innovation officer.
  
• Speaking of IPG, its merger deal with Omnicom is set for more regulatory scrutiny. Britain’s Competitions and Markets Authority — the same CMA which hounded Google’s efforts to sunset the third-party cookie — has launched an official inquiry into the deal.
  
• Yoshinobu Ise has been appointed as the global head of sports and entertainment at Dentsu; the firm has pushed its sports unit into the Middle East and North Africa region. It’s also expanded its specialist anime unit into North America, China and South East Asia — the first time it’s offered anime licensing and merch services outside Japan.
  
• Elsewhere, Dentsu’s Merkle appointed Chris Freeland as CEO in the U.K. and Ireland, while Nadine Young has been appointed CEO of Publicis media shop Spark Foundry, after predecessor Emil Bielski stepped down.
  
• PMG followed its acquisition of Momentum last week by unveiling a martech marketplace called Alli, which allows marketers to toggle on and off apps in the media buying and planning workflow at a click.
  
• Havas launched an AI creative tool named after the Dutch artist Johannes Vermeer (he painted Girl With A Pearl Earring) this week. But the AI investments aren’t just limited to holdcos — indie full-service agency Mod Op is set to invest $11 million into AI and data science over the course of 2025.

Direct quote

“While Google is fighting these antitrust cases it’s not able to focus completely on the business. Amazon, on the other hand, is making moves. They’re who Google should be worried about.”

— A frank assessment of one of this year’s big dramas, overheard in Cannes by Digiday’s editors

Speed reading

• Last week was inevitably dominated by news and notes coming from the Riviera. We covered the focus among dealmakers and execs on two of the industry’s great obsessions – the creator economy and AI. Michael Bürgi covered a beachside blitz from Omnicom, which unveiled strategic partnerships with YouTube, Amazon, Meta, Disney, Walmart PayPal and X during the week. And as President Donald Trump kicked the TikTok can down the road once again, Krystal Scanlon reported on the marketers buttonholing the platform’s execs for answers. You can find the rest of our Cannes coverage here. She also profiled Unik Ernest, one of the Croisette’s most prolific fixers. 
  
• Jess Davies wrote about The Guardian’s move to consolidate its programmatic operations and lean further into curation.
  
• Finally, if you’d like to read something that’s got nothing to do with France, I penned a piece looking at top brands investing in digital out-of-home — including a Sprite campaign that uses heat and humidity-activated billboards.