Display / Video campaigns: cheap inventory is costing you more than you’d think

Fraud and invalid traffic

Even if two ads are technically displayed on a screen, the context, the quality of the environment, the actual visibility, and the attention they generate can be radically different.
A significant portion of programmatic inventory is now plagued by forms of artificial traffic, generated not by humans, but by bots, scripts, or domain spoofing techniques.  

Among the most common methods are:  

• Ad stacking, where multiple ads are layered on top of each other but only one is actually visible  

• Impressions on fake sites posing as premium publishers  

• Automated traffic generated in loops to artificially inflate metrics 

According to the 2025 European Ad Fraud Savings Report, up to 10% of programmatic spending is absorbed by invalid traffic – representing several billion euros per year across the market. Beyond simply wasting budget, this distorts KPIs, pollutes performance reports and can lead to misguided decisions in terms of targeting or media strategy. 

Low viewability rate and attention

Even if an impression is technically displayed, this doesn’t guarantee that someone has actually seen it, or paid attention to it. Many campaigns running on low CPM inventory may still report high viewability rates, but in reality, the user might be scrolling past, not looking at the screen, or engaging with entirely different content. 

In many cases, ads are placed in areas of the page that users rarely look at. This gap between viewability and actual attention is crucial. Cheap placements check the viewability box, but fail to generate meaningful attention. And without true attention, there's no brand recall, no impact, and ultimately, no performance. 

At iO, we use IAS’s Quality Attention solution to measure and optimise the real impact of our campaigns. By combining eye-tracking data (powered by Lumen) with media quality signals like viewability, ad clutter and user interaction, IAS helps us identify placements that truly capture attention, not just impressions. This allows us to focus on high-quality environments that drive stronger engagement and better performance. 

Brand safety & contextualisation

An ultra-low CPM often reflects inventory distributed in poorly controlled environments, where the risk of inappropriate, extreme or simply irrelevant content is much higher. In these types of contexts, the brand may appear alongside conspiracy theories, fake news, violent content or in locations completely unrelated to its universe.  

The danger is twofold: on the one hand, it can directly damage the brand image (bad buzz, loss of credibility, potential boycott), and on the other hand, it greatly dilutes the relevance of the advertising message, which ends up lost in an environment that doesn’t correspond to it.  

Attention, brand lift and real performance

Premium inventories – such as those offered by publishers such as DPG Media, Rossel and Roularta – offer reliable, relevant and brand-safe editorial environments. Their CPM may be higher, but this cost reflects better exposure quality: visible placements in engaging contexts, reaching real and qualified audiences.  

The result: natural amplification of the message, better brand lift, greater engagement and a measurable increase in post-impression conversions. 

Example with Lidl: we conducted a test comparing lower-cost ad placements with more premium ones. While the CPM of premium placements was 28% higher, the results showed clear added value: the bounce rate dropped by 31% and the average session duration increased by 33%. This led to more qualified visits and higher engagement on the website, demonstrating the impact of investing in premium placements. 

Transparency and supply chain optimisation

In programmatic buying, each impression goes through a chain of intermediaries (DSPs, SSPs, ad exchanges, etc.). The longer and more opaque this chain is, the more difficult it becomes to know where the budget is actually going. This opens the door to hidden costs, duplicate bids, or purchases of low-quality inventory – often without the advertiser's knowledge.  

Supply chain optimisation reduces these inefficiencies by promoting direct, transparent and reliable purchasing paths. By collaborating with identified and verified partners, we maximise the value of each impression while improving the quality of the environments in which ads are displayed. 

Contextual alignment and brand consistency

The context in which an advertisement appears directly influences how it is perceived. Placing an ad in an editorial environment that is consistent with the values, tone or interests of the target audience helps to reinforce its credibility, capture more attention and generate a stronger emotional impact. 

This is the whole point of contextualised inventory, available in particular through premium websites: a campaign for a financial service in an economics section, a tech product in an innovation media outlet, or a lifestyle brand in a women's magazine. This “brand-content fit” improves the relevance of the message, increases engagement and promotes an advertising experience that is perceived as more natural and less intrusive. 

A low CPM may seem attractive... but the actual impact on the brand is often inversely proportional to the price paid. Cheap inventory is often associated with low visibility, poorly qualified audiences and even ad fraud. And in the end, what was supposed to cost less... ends up costing more. 

At iO, we believe that every euro invested should create value – not just generate impressions. That's why we prioritise:  

• Direct collaboration with leading premium publishers such as DPG Media, Roularta, Rossel, etc.  

• The use of pre-bid verification tools to proactively block suspicious or non-compliant impressions 

• The selection of manually verified inventories to guarantee a safe, relevant and high-performing context for our clients