12 spots left to attend the Digiday Programmatic Marketing Summit

WPP surprised the marketing and media worlds today with the least-surprising news possible. The agency holding company said it is purchasing InfoSum — the data firm once run by its current global CEO of GroupM, Brian Lesser. From the day Lesser took the reins at GroupM last July, it’s been speculated that WPP might purchase the firm — and now it has.
Terms of the deal were not disclosed. Sources close to WPP said InfoSum’s last valuation was $300 million.
But the deal represents a leveling-up on WPP’s part in the data-driven arms race among the agency holding companies. It comes just weeks after Publicis purchased Lotame, and months after Omnicom moved to acquire Interpublic Group, which comes with Acxiom.
“New York made its move” with Omnicom moving to purchase IPG last year, said Jay Pattisall, vp and senior agency analyst at Forrester. He said he remembers thinking, “Let’s see how Paris and London react. We now have seen how Paris [Publicis’ HQ] and London [WPP’s HQ] are reacting, in that they’re strengthening their data capabilities in order to have a similar impactful activation strategy for their clients.”
Observers of the media landscape credit WPP with buying a company it already knows something about. “That’s about as good due diligence as you can do when you’re buying a business is employ the CEO first,” quipped Sam Tomlinson, chief client officer at consultancy MediaSense. “Lesser, of all people, should know Infosum’s strengths and possible weaknesses.”
What does the purchase do for WPP? According to global CEO Mark Read and Lesser, it’s about positioning the holdco’s ability to incorporate clients’ first-party data in future-leaning, open-sourced ways rather than relying on traditional forms of identifiers.
“I felt like the marketing and advertising world was taking a very myopic view around customer identity and trying to ground that identity in old forms of technology like email addresses,” Lesser told Digiday. “As far as our data strategy is concerned … we think the future is open, not closed. We think the future incorporates all sources of data, not one singular database.”
One consultant who spoke on condition of anonymity, generally agreed with Lesser’s positioning. “When you look at the other big holdco strategies around data, you’ve got Publicis whose strategy is, use our Epsilon data,” said the consultant. “You’ve got Omnicom, who, once they get their hands on IPG and Acxiom, will be saying use our Acxiom data. Whereas WPP are basically saying, use your data in our tools. And that fits with what WPP have been consistently saying — we’re data agnostic, we’re not trying to sell you our data.”
InfoSum specializes in creating clean-room environments where first-party data from brands can safely be cross-referenced with publisher and other marketing intelligence and audience data. It’s a difference from what the other holdcos have done.
“The data clean room solutions that that Infosum provides is arguably more superior than than some of the legacy solutions that Epsilon, Acxiom have — and I don’t think Lotame has any clean room” offering, added Pattisall.
“It fits with the WPP strategy of using the client’s data,” said MediaSense’s Tomlinson. “Time will tell whether that proves to be a better strategy than Publicis using Epsilon and Omnicom, in due course, using Acxiom.”
Because everyone is a critic, one source with some knowledge of the ad-tech marketplace, said they believed InfoSum had a limited future as a standalone business, which could have hastened WPP’s purchase. “I didn’t think InfoSum was doing much and was just treading water. … This seems like [Lesser] wanted to save his investments and make millions in the process there and ended up acquiring it,” said the source.
While WPP said it will house InfoSum within GroupM — and its CEO Lauren Wetzel becomes global chief solutions officer for GroupM — it will also help to train models in WPP’s Open platform, which houses the giant’s AI tools, tech and abilities.
“I think that AI allows us to be much more sophisticated in terms of analyzing data and patterns in ways that perhaps we don’t understand or could never understand as people, but can do so in a privacy compliant way, and that is the power that InfoSum brings us,” Read told Digiday. “The other half of it is, not only does it allow us to get insights from data that we wouldn’t ordinarily be able to find, it enables us to use those in media that traditional CRM systems can’t because of the limitations around cookies and email identifiers. It’s very hard to use them in walled gardens.”
“Brian has been bold in teasing out his vision since returning to WPP,” said Matt Barash, an ad-tech veteran who argues the secret weapon to this deal is bringing Wetzel into GroupM. “WPP is zigging while other holdcos zag. Their competitors have built data strategies built on legacy CRM tech as their core foundation. WPP is moving towards a federated data model which is more privacy friendly and combined with AI modeling scalable.”
“He’s been vocal about modernizing and using technology as a competitive advantage, whether it be their AI platform, WPP Open or his vision for AI addressability,” added Barash.
Is there a downside to the progress WPP and GroupM are making in incorporating more and more AI into the media process? To some insiders at GroupM, when they hear Lesser talk about no humans touching media planning in five years, it’s deeply disturbing not only from a redundancy standpoint but just from a human standpoint.
Finally, there’s the question of Lesser’s stake in InfoSum. If he retained a stake in the company, then he stands to make a killing through WPP’s acquisition. Neither Lesser nor WPP offered a comment.
More in Media Buying

WTF are gray bots?
AI agents, scrapers and crawlers powering the agentic era are quietly reshaping the web — and potentially the digital economy.

Media Buying Briefing: Millennial parents and their Gen Alpha kids are upending consumption habits: Horizon study
This new set of families have an influence on each other’s consuming habits unlike prior generations.

Ad Tech Briefing: Has Google sacrificed Privacy Sandbox on the altar of antitrust concerns?
Taking the L of a U-turn on third-party cookies could be worth it to save the Golden Goose of Chrome.