This story was originally published in Digiday.

In the second of a series of moves Omnicom is making at this week’s Cannes Lions Festival of Creativity, the agency holding company today struck a strategic partnership with e-commerce player Instacart that involves sharing of data and measurement that can more directly tie sales to TV advertising.

Arguably the most interesting part of this deal involves Instacart building a data pathway to allow it to work with the clean-room infrastructure Omnicom recently built in its Omni marketing orchestration platform. That clean-room setup accesses OMG partnerships with NBC and Disney for planning and measurement.

Instacart is essentially weaponizing the troves of sales data it has from consumers searching for and purchasing products online, to the benefit of ad agencies and consumer packaged goods brands, who will be able to measure impact and drive sales more effectively armed with that data.

Megan Pagliuca, Omnicom Media Group’s chief activation officer, explained the partnership pushes forward OMG’s goal to deliver analytics across various aspects of a brand’s media investment, enabling enhanced measurement to help prove advertising spend and value.

“We can now see the people that watched Hulu or NBC, then went and made a purchase via Instacart,” said Pagliuca. “That’s huge, because think about how traditional linear [TV buying] has been [about] GRPs or reach and frequency. And now it’s about, ‘Hey, did you see an ad and add it to your Instacart list and buy it?’”

“For example, in the future, home cleaning brands can better understand how their ads on Hulu drove purchase of their products on Instacart,” added Ryan Mayward, Instacart’s vp of  ad sales. “We can also dive deep on basket analysis and content consumption trends with Omnicom to help that cleaning supplies brand understand which products resonate most with audiences. The goal is to give CPG brands the data and shopping insights they need to better understand their business and identify growth opportunities.”

“Data is the oil, e-commerce or digital experience is the vessel or vehicle, and media is the engine that propels it forward,” said Jay Pattisall, vp and agency analyst at Forrester. “All of these things are kind of moving in tandem, and it’s part of the arms race of staying competitive in a really fast moving digital environment.”

Pagliuca also noted this move offers yet another step forward in the melding of brand and shopper budgets within agencies and among CPG brands. “Now that you see that [wall between brand and shopper] collapsing … you’re going to get much better results when you’re looking at this together, rather than looking at it as in a silo.”