IAB Europe today published a 16-minute episode of its Retail Media Roundtable podcast in which Lisa Avery of Zitcha described a beer promotion that looked like a winner on return on ad spend while it moved shoppers to a cheaper pack and left the retailer with lower product margin.

The conversation was recorded live at IAB Europe's Retail Media Impact Summit in Amsterdam on October 7, 2026, and hosted by Jason Wescott, Global Head of Commerce Solutions at WPP Media and chair of IAB Europe's Retail & Commerce Media Committee. Titled "The Credibility Gap: Why Retail Media Struggles to Win Merchant Buy-In," it follows a workshop Avery led at the summit under almost the same name. Her argument is simple to state and hard to fix: retail media teams and the merchants who buy stock for a retailer measure success in different units, and the distance between those units has cost retail media trust inside the companies that run it.

In Short

Retail media teams often celebrate high return-on-ad-spend figures, but the buyers who order stock for a retailer care about sell-through, margin and turnover, and those numbers rarely appear in campaign reports. Zitcha's Lisa Avery told IAB Europe's podcast that this mismatch is why many retail media networks still sit apart from the retail business that hosts them. Her case rests on unnamed examples, including an Australian beer promotion whose advertising results looked strong while the retailer lost margin.

From an Amsterdam workshop to YouTube

IAB Europe's second Retail Media Impact Summit took place on October 7, 2026, at Felix Meritis on Amsterdam's Keizersgracht, according to IAB Europe's event page, which describes the edition as sold out and says over 200 industry leaders attended. The first edition, on September 24, 2025, at the Tobacco Theatre in Amsterdam, drew more than 150 senior European retail media leaders, according to IAB Europe. Wescott hosted the 2026 day.

Avery's session appeared on the summit agenda as "The Credibility Gap: Why Retail Media Still Struggles to Win Merchant Buy-In," an interactive workshop that ran from 13:30 to 14:15 in the Zuilenzaal, hosted by Yara Daher of IAB Europe, according to the agenda. The YouTube episode drops the word "Still." Zitcha was among the summit's headline sponsors, according to the same page. Earlier that morning, Wescott moderated a brand panel, "The Brand Perspective: What Drives Value for Advertisers in Retail Media," with panellists from Unilever, Henkel and Heineken, according to the agenda. Avery referred to that panel at the start of the recording.

The same day, IAB Europe also used the summit to announce that Moloco had become the first ad tech provider to complete its retail media certification programme, the third certified company after Albert Heijn and Nectar360.

The episode sits in IAB Europe's Retail Media Roundtable Podcast playlist on YouTube, which listed 21 episodes on publication day. IAB Europe recorded ten episodes at the 2025 summit and published them in a round-up on December 16, 2025. On November 6, 2026, it released three more recorded at the 2026 edition, in a series it says is sponsored by Mirakl Ads.

There is one discrepancy in how the guest is introduced. In the recording, Avery describes herself as "the VP of EMEA for Zitcha." The YouTube description and the summit's speaker list both give her title as Director of Customer Success EMEA, according to IAB Europe. Neither source explains the difference.

Avery described her company in one line: "Zitcha is a retail media orchestration platform working with networks to get everything up running and grow within the industry." The company began in Australia and opened a UK office in March 2024, according to Mi-3, and raised a A$15 million Series A round led by VMG Partners in September 2024 to expand in the United States, according to Retail Technology Innovation Hub. It sells software to the networks whose credibility problem she was describing, a point she acknowledged with a joke near the end of the episode.

Two reasons the gap persists

Wescott opened by asking what had stood out at the summit. Avery named Daniel Knapp, IAB Europe's chief economist, whose morning keynote, according to the agenda, covered new data on how European retailers use sponsored product inventory. The recording does not repeat any of his figures. She then turned to the brand panel, saying it reinforced her view that "measurement hasn't really moved on enough and there's still too much fragmentation."

Brands, in her telling, are "really struggling to get a true idea of what a campaign runs." The metric media teams lean on, ROAS - the revenue credited to advertising divided by its cost - "is a signal, but it's not the only thing," she said. She went further: "I think the industry has used it as a bit of a crutch for so long ... that now we're getting to the point where something has to change." Nobody, she added, is "really sure where to change to."

Asked why the credibility gap with commercial teams still exists, Avery gave two reasons.

The first is organisational: many retail media networks, in her account, were built as separate units inside the retailer. "In a lot of networks where retail media networks have been set up within a retail environment, they actually sit quite a lot in a silo from the broader retail business," she said. "So yes, they provide a really strong margin and revenue stream, but the retailer just sees them more as kind of like a high margin add-on rather than actually helping drive their retail business." The consequence, she said, is that "retail media has kind of become this sideshow and has almost become slightly more media, slightly less retail I think over the last few years."

The second is vocabulary. Media teams share impressions and, above all, ROAS. "So many of them shout about ROAS so much which is kind of it's a signal. It's an attributed sale," Avery said. The commercial side, she argued, works with different numbers entirely: "what the commercial teams care about, I don't think any of them really even know what that is. They care about stock sell-through, profit margins, you know, like what's my turnover."

The 100x exchange

The example she chose to illustrate the clash was blunt. Media teams, she said, present examples "even like 100x ROAS and the guy there is like well I haven't ordered any more products. So, well, how can you possibly tell me that you have like generated 100% return when I still have the same products on my shelf and you're not driving my sell-through? And I think because of that, you kind of break the trust."

The arithmetic in that exchange does not line up. A ROAS of 100x means attributed revenue equal to 100 times the advertising cost - 10,000% of the spend, not 100%. The slip does not weaken her point, which concerns what the figure leaves out rather than its size: attributed sales can climb while orders placed with the supplier, stock on the shelf and the retailer's margin stay where they were. Avery did not name the network or campaign behind the 100x figure. She said she would share examples later in her presentation; those slides are not part of the episode.

Wescott agreed. "If this retail media thing is not driving more sales and ... it's not actually driving more business growth for the retailers, then what's the point?" he asked. Avery's reply was the sharpest line of the conversation: "It's just so funny that nothing that we report on as standard out of the box anywhere actually ties to selling products, which is what everyone is there for." Her diagnosis of why: "it's because we don't have the right people in the room in my opinion anyway."

A promotion that looked like a winner

Wescott then asked how retailers can connect media metrics to sell-through, inventory and category performance. Avery's first answer was, by her own description, "a really boring answer": "cultural and governance change." "You don't change kind of like systemic cultural issues like this overnight," she said.

The practical lever, in her account, is to put the commercial team's own measures into media reporting. Zitcha has been "running some data crunching and ... almost pilots" with "a lot of our retailers," she said, to show "how has it affected my speed of sell-through? How has it affected my profit line? Like how has it had an impact on my category share of voice and what does that look like?" She did not say how many retailers took part. Artificial intelligence, she argued, is what makes this feasible now, where before "you'd need to hire an army to get you to this data."

Then came the beer. "It was a liquor company ... actually over in Australia," Avery said, "but what they had is they had a price promotion I think on like a four-pack of beer." The budget was "a decent budget as well," split between on-site and offsite placements, and the ROAS "looked great." The team's verdict was "this is a winner."

The underlying data told another story. "When we actually drilled into the data ... and looked under the surface, yes, they had sold more of the four-pack product, but actually what they'd done is cannibalize a more expensive six-pack," she said. "And so people had actually bought less overall at a lower product margin."

Seen from the merchandiser's desk, the picture was worse still. "Yes, they sold more packs, but actually they were left with more six-packs than they would normally have on the shelf," Avery said. "And actually, that ate into their product margin because it was on promotion." Was that, she asked, "a wise decision for retail? ... Not just media income."

Why ROAS missed it

The mechanism is not exotic. ROAS credits sales of the promoted product to the advertising; it does not subtract the sales the same shoppers would have made on a substitute. When a discounted four-pack draws buyers who would otherwise have taken a more expensive six-pack, the campaign report records the four-pack sales as a gain. The category ledger records less beer sold, a lower average price and six-packs left on the shelf. Both reports can be accurate at the same time, and they point in opposite directions.

Avery's conclusion was that the value of the analysis lies in planning, not post-mortems. With that information "up front," she said, the brand "probably would plan not only the media activity, but the promotional activity attached to it in a really different way as well." The aim is "first of all just to turn the lights on," and secondly "to better inform our decision-making in the future."

Wescott framed it as a strategy question. "In order to be strategic, you need to bring these two things together, right?" he said. "If they're going off and doing their own things in a silo, it's only going to be tactical."

The example comes without the details that would allow anyone to check it. The episode names no retailer, no brewer, no campaign dates, no budget, no ROAS figure and no method for the analysis, and Avery's "I think" qualifies even the pack size.

What data the commercial side wants

Wescott's next question was what evidence actually convinces commercial teams. Avery laid out a sequence, starting with data most retailers already have and ending with data they guard most closely.

The starting point is "overall sales and sales price across ... not just online but if you can include your offline data in that across the board." That allows a network to show "impact on category, impact on sales numbers, impact on stock levels." The next layer is "your promotional or trade calendars," which reveal whether a product was selling below its normal price. The final layer, which she called "the holy grail," is product margin, which is also "as a retailer always the hardest to get your hands on."

Brands, she said, would weigh those measures differently. "If I was a brand I'd care about not only kind of visibility and building my brand in the market but I would care about is it driving more sell-through? Is this business ordering more of my products next season and is this making a difference to my bottom line?" Margin matters less to some suppliers: "Some brands have more static ... product margin so maybe they care about that less but that is more of that real retailer metric."

Sharing that data does not have to mean handing it over. "You can do kind of data sharing and you don't have to just send data," Avery said, "but I think getting the data people on side and in a room as part of that conversation ... is a really big thing." She did not name a specific technique.

Wescott summarised the problem in a familiar phrase: "We've always been data rich just insight poor." AI, he said, changes the staffing equation: "instead of needing a team of like 20 people we might need a couple of people and it can run all of these ... models."

The weight Avery gives to offline data reflects how retail still works in markets like the one her example came from. In Australia, about 85% to 90% of sales still happen in store, speakers told IAB Australia's retail media summit in July 2026, where a market of just over $2 billion was described as facing a measurement gap. At the same Sydney event, Metcash's Mark Lollback said, "I don't know any other media form in this country that the only focus is on incrementality."

A question before a dashboard

Asked what a retailer should prioritise first to close the gap, Avery opened with a sales line - "Oh, obviously about outside of coming to talk to us" - and then gave an answer that involves no software.

"I would sit down in a room with whoever it is in your business who is responsible for the other side of your brand relationships," she said. "If it's trade, if it's commercial buyers, whoever it is, and actually just ask them, are they seeing the impact of the media that we're running on their bottom line and the business we're doing?" Going in with a performance pitch, she argued, will fail with experienced buyers: "if you just go on the attack ... I don't think that's going to work. You need to win them over culturally."

Cooperation of that kind is uncommon among the networks Zitcha deals with, in her account. "We've got a few examples where they're really good at working together, but I would say they're more in the minority," she said. Those tend to be retailers "where we've got things like CEO support for what we're doing from a retail media perspective." She added: "Not every business is blessed with that."

Wescott said the advice matched a keynote on transformation he was due to give "in a couple of weeks," without naming the event. Asked to sum up the summit in a few words, Avery settled on "thought-provoking conversations."

What IAB Europe's own numbers show

The podcast arrived six days after the committee Wescott chairs published research that maps closely onto Avery's argument. IAB Europe's third Attitudes to Retail Media Report, released on November 3, 2026, found that the share of European buyers asking for ROAS fell from 89% to 49%, while lack of available data as a barrier to investment rose from 31% to 58%. Across the full sample of 150 respondents, 58% of buyers wanted multi-touch attribution against 31% of sellers offering it. If buyers are losing interest in ROAS, Avery's account suggests that many networks have not yet replaced it with anything their own merchants recognise.

That report's previous edition, published in July 2025, had 88% of buyers demanding ROAS from a base of 180 respondents in 31 markets. Wescott presented those findings in a webinar on July 30, 2025, when the share of brands working with four to six networks had risen from 10% to 24%.

The market behind those surveys is large and still growing. IAB Europe's AdEx Benchmark 2025, released on July 7, 2026, put European retail media at 13.314 billion euros, up 16.7%, and above 10% of total digital ad spend for the first time. At Cannes in June 2026, IAB Europe pointed to its own January 2026 survey in which 70% of advertisers reported frustration with performance measurement.

Research from outside IAB Europe points the same way. A survey of 281 professionals by SMG, the IAB and IAB UK found that 46% of brands named proven, measurable ROI and incremental sales impact as what would persuade them to invest more, and 34% ranked reporting as the least connected part of commerce media. Incremental, a measurement vendor, estimated in June 2026 that siloed attribution misses 36% to 53% of total retail media impact - a finding about effects outside a single retailer, the mirror image of Avery's beer case, where effects inside the retailer cancelled each other out. In November 2025, the IAB and IAB Europe published guidelines that rank incremental measurement methods by causal strength, separating incrementality from attribution.

ROAS claims continue to be published without the detail needed to judge them. In October 2026, The Trade Desk claimed 41% higher ROAS for retail data targeting without disclosing a sample size.

Why it matters for marketers

The money at stake has grown. WPP Media's This Year Next Year forecast, released on December 10, 2025, estimated that commerce advertising reached $178.2 billion in 2025, surpassing television for the first time. Wescott, who hosted this episode, runs commerce solutions for the same agency group.

For brands, the conversation describes a shift in who judges a retail media campaign. At present the verdict usually comes from the network's media team and the brand's media agency, in the currency of attributed sales. Avery's version adds the retailer's merchant to the jury, and the merchant asks different questions: did the promotion pull sales from a higher-margin line, did the supplier receive more orders, is the shelf emptier than it would have been? Campaigns that score well on the first set of questions can score badly on the second, as her beer example shows.

For retailers, the argument is about where a retail media network sits. A network run as a high-margin add-on can report rising revenue while its campaigns quietly cannibalise categories and erode product margin - the outcome Avery described in Australia. A network wired into merchandising data can, at least in principle, plan media and promotions together. Whether networks will share product margin data, which Avery called the hardest data to obtain, is a question the episode raises but does not answer.

The episode is a conversation, not a study, and it comes from a vendor with a commercial interest in the problem it describes. IAB Europe's own data supports the argument in outline: buyers are moving away from ROAS, and sellers are still selling it.

Timeline

Summary

Who: IAB Europe, which published the episode; Lisa Avery of Zitcha, an Australian-founded retail media software company, introduced in the recording as VP of EMEA and listed by IAB Europe as Director of Customer Success EMEA; and Jason Wescott, Global Head of Commerce Solutions at WPP Media and chair of IAB Europe's Retail & Commerce Media Committee, who hosted.

What: A 16-minute Retail Media Roundtable podcast episode, "The Credibility Gap: Why Retail Media Struggles to Win Merchant Buy-In," arguing that retail media networks lose credibility with merchants and commercial teams because they report ROAS and impressions rather than sell-through, stock levels, turnover and product margin. Avery's main example was an unnamed Australian liquor company's beer promotion that showed strong ROAS while cannibalising a more expensive six-pack and reducing the retailer's product margin.

When: Recorded on October 7, 2026, and published on YouTube on November 9, 2026.

Where: Recorded at IAB Europe's second Retail Media Impact Summit at Felix Meritis in Amsterdam; the beer example took place in Australia.

Why: The episode lands days after IAB Europe's own survey found ROAS demand among European buyers falling from 89% to 49%. It frames the next stage of retail media measurement as a question of whether networks can report in the retailer's own commercial metrics, including margin data that retailers rarely share.