Retail media is growing fast, and Sam’s Club’s Member Access Platform, just over a year old, is growing even faster. At least part of the reason may be innovation in sharing data and allowing third-party measurement.

In this week's Marketer's Brief podcast, Austin Leonard, head of sales for the Sam’s Club MAP program, talks about how marketers are using insights the platform has provided about member purchases to shape their digital ad buys across not just Sam’s Club properties but also the open web. He also talks about why MAP early on embraced third-party measurement and analytics from Circana (formerly IRI).

Group M projects retail media will grow nearly 10% this year to more than $125 billion in spending. Sam’s Club is growing at three times that pace, with Walmart, its corporate parent, reporting the unit’s advertising revenue grew 33% last quarter.

Giving brand marketers better data and insights to work with plays a role. Sam’s Club earlier this year launched a program to let brands target shoppers based on their club purchase history across the open web via The Trade Desk. So marketers of TV sets can stop bombarding people who already bought one at Sam’s, or ads can be targeted to complement an order someone is picking up at curbside.

“We’re seeing an average improvement of about 30% on [return on advertising spending] for all advertisers that are leveraging this,” Leonard said. “They get full visibility for the member journey from intent to purchase.”

That included a recent collaboration with Clorox Co.’s Kingsford charcoal around grilling during a Sam’s Club 40th anniversary celebration this year, which he said exceeded the brand’s expectations by about 20% when combining digital and in-person events.

Focusing on third-party measurement, standards and partnerships is also helping drive business, Leonard said, which includes getting Interactive Advertising Bureau certification, working with The Trade Desk to get access to better inventory off Sam’s-owned sites and using Circana for third-party measurement.

“We’re one of the few if only major retail networks that have leveraged a third party so we’re not grading our own homework,” Leonard said. “We’re trying to meet those standards of advertisers, not just the shopper marketing teams, but also the national brand standards of media and really help make sure that we can deliver capabilities that live up to those standards.”