Bad Ads in Programmatic Advertising: What Publishers Should Know

If you’ve noticed more inappropriate or misleading ads slipping through lately, you’re not alone. Across the programmatic ecosystem, publishers are reporting a spike in what we’d call “bad ads” — the kind that don’t just look out of place, but can seriously impact the user experience and erode trust in your brand.

These aren’t necessarily malicious or fraudulent ads. In many cases, they’re ads that were mislabelled, disguised, or slipped past filters due to gaps in enforcement or transparency. For example, an ad promoting gambling content might be categorized as “entertainment” or even “family-friendly” to access more inventory than it should.

At Publisher Collective, we’ve been keeping a close eye on these patterns — and we’re taking steps to strengthen our protections. In this post, we’ll explain what bad ads are, why they appear, and how both the industry and our team are working to keep them off your site.

What Counts as a Bad Ad?

The term “bad ad” gets thrown around a lot, but in the world of programmatic advertising, it has a pretty specific meaning. We’re not talking about malware or obvious scams — we’re talking about ads that don’t belong on your site.

A bad ad is one that:

• Is inappropriate for your audience (like gambling, adult content, or sensational clickbait)
• Misrepresents what it’s selling (for example, ads that use misleading images or false urgency
• Feels out of place or damaging to your site’s reputation — even if it’s technically allowed

These ads often look legitimate at first glance, but the problem lies in how they’re labelled, where they’re shown, and how they align (or don’t) with your content and community.

Bad Ads vs. Malvertising vs. Fraud: What’s the Difference?

To make things clearer, here’s how we distinguish between common ad quality issues:

Bad ads often fall into a grey area. They aren’t trying to infect a device or steal data, but they still create a negative experience for users, and for publishers, that matters.

Even one poorly matched ad can lead to complaints, reduced time on site, or loss of trust. And when users don’t trust the ads they see, they’re more likely to block them entirely, which causes a whole different set of problems.

Why Bad Ads Appear in the First Place

With so many checks, filters, and rules in place, it’s fair to ask — how are bad ads still getting through?

The short answer: automation isn’t perfect, and not all players in the programmatic supply chain enforce the same standards.

Here’s how it usually happens:

1. Mislabelled Categories

Advertisers want access to high-performing inventory. One way to get it is by misclassifying their ads. For example, a gambling ad might be tagged as “entertainment” or “general interest” to increase its chances of serving, even if it’s completely inappropriate for the site.

Because programmatic systems rely on metadata like categories and labels, mislabelled ads can slip past filters, especially if the SSP or DSP doesn’t verify the tags closely.

2. Cloaking or Creative Swapping

Some advertisers submit a clean version of a creative to get past approval, then switch it out after it’s live. This tactic — known as creative swapping — is designed to bypass manual checks and automated scans.

3. Inconsistent Enforcement Across Platforms

The programmatic chain includes multiple parties: DSPs, SSPs, ad exchanges, and verification vendors. Some are stricter than others when it comes to enforcement. An ad that gets flagged on one exchange might still run through another.

Even with best efforts, a single weak link in the chain can let a bad ad through.

4. Gaps in Transparency

The industry has developed standards to improve transparency and trust in programmatic buying, including:

• ads.txt: Allows publishers to declare who is authorized to sell their inventory
• sellers.json: Helps buyers see who is reselling the inventory
• SupplyChain Object: Shows the full chain of parties involved in a bid request

These tools are valuable, but they don’t catch everything. If a bad actor is using a legitimate reseller or if metadata is manipulated, bad ads can still find a way in.

That’s why fighting bad ads isn’t just about having filters. It’s about constant vigilance, collaboration across the supply chain, and being ready to act when something gets through.

How Publisher Collective Tackles Bad Ads

Stopping bad ads entirely isn’t always possible, but we work hard to limit them and act quickly when they appear. Our goal is to make sure your audience has a positive experience, and that any issues are dealt with as soon as they come up.

Here’s how we approach it:

We Monitor Ad Quality Every Day

We keep an eye on the types of ads being served across our network. If anything looks out of place or inappropriate for the context, we investigate and take action. This might include blocking specific creatives or adjusting settings to limit certain ad categories.

We Use Category Filters to Prevent Mismatches

Different publishers have different audiences and standards. That’s why we apply category filters to help control what kinds of ads are allowed to run. If you don’t want to show ads related to gambling, dating, or other sensitive topics, we’ll work with you to respect that.

We Continuously Review and Adapt

We rely on publisher feedback to improve how we manage ad quality. When we see recurring issues — whether it’s a certain ad type or a gap in filtering — we use that input to strengthen our approach and reduce the chance of similar issues happening again.

Investing in Advanced Detection Tools

Fraudsters and bad actors are always evolving their tactics. That is why we partner with industry-leading experts in bad ad detection, such as The Media Trust. Their technology helps us catch and block millions of bad ads that would otherwise reach publishers’ audiences. By working closely with these experts and contributing feedback from our network, we ensure we are using the latest detection methods and staying ahead of emerging threats.

Working With the Right SSPs

Ad quality is a shared responsibility. We work closely with our SSP partners to make sure category filters are respected and ad content is properly reviewed. If a platform consistently allows mislabelled or inappropriate ads through, we raise the issue — and if there’s no progress, we re-evaluate the relationship.

We only want to work with partners who are aligned with our standards and our publishers’ needs.

We know how frustrating it is to see an ad that doesn’t belong on your site. There’s no switch that guarantees a perfect setup, but we stay transparent, responsive, and focused on continuous improvement. That way, you can concentrate on your content and community, knowing that we’re working hard behind the scenes to protect both.

Final Thoughts: Staying Ahead of Bad Ads

Bad ads are an industry-wide challenge. As long as programmatic advertising relies on automation, there’s always a chance that something inappropriate, misleading, or mislabelled will make it through. But that doesn’t mean publishers are powerless or left to deal with it alone.

At Publisher Collective, we believe ad quality matters just as much as revenue. That’s why we stay proactive, build strong relationships with trusted partners, and make sure publishers have support when something goes wrong.

If you have questions about how we manage ad quality or want to talk through your own setup, get in touch with us here.