Wal-Mart Stores Inc. is getting serious about moving into the digital advertising business.

The retail giant today announced its intent to acquire an advertising startup called Polymorph Labs Inc., which sells a cloud-based “self-serve platform” for online ad publishers.

In a statement posted on its website Thursday, Stefanie Jay, vice president and general manager of the Walmart Media Group, said the retailer has been quietly building its advertising business for some time already, and that the Polymorph acquisition is a key part of those plans.

“This technology complements Walmart’s current omnichannel ad targeting and measurement solution, and will provide a platform for continued future innovation, such as real-time auctions across multiple ad-pricing models (cost per click, cost per impression, cost per conversion),” Jay wrote.

The idea, as always within advertising, is to help advertisers deliver more relevant ads to people using Walmart’s online shopping websites. Polymorph’s team will join the Walmart Media Group, which is the company’s newly formed advertising unit.

Polymorph’s ad platform is said to encompass a high-speed server, a self-serve interface and server-side header bidding tools, TechCrunch reported. Those tools should help Walmart make it much easier for brands to target specific kinds of customers based on their shopping behavior, and deliver more relevant ads to them, Jay said. For example, an advertiser could target a dog food buyer with cat food ads, automate the delivery of these ads and then measure how successful they are.

Polymorph’s platform is said to complement Walmart’s existing ad tech, which includes its omnichannel ad targeting and measurement tools.

“Simply put, we can help brands understand if someone saw their ad on Walmart’s platform or across the internet, and then purchased the product in-store or online,” Jay continued. “No one else can do this at scale like Walmart.”

The acquisition underlines just how serious Walmart is about leveraging its massive scale to compete in what is essentially an entirely new business for the company. Its target audience certainly makes the effort worthwhile, though, with Walmart claiming its stores and websites attract 160 million shoppers every week.

Walmart’s move into advertising was first revealed by Bloomberg in February. That report said it was motivated by the resounding success of one of its biggest retail rivals, Amazon.com Inc.

“We have a tiny ad business,” Walmart Chief Executive Doug McMillon told investors last October, according to Bloomberg’s report. “It could be bigger.”

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