In her latest piece, the inimitable Shirley Marschall looks at why toenail fungus is the true measure of ad tech done badly…

We've all been there. Browsing a high quality news site or app, reading an interesting article all the way to the end, still thinking about what we just read, maybe looking forward to discovering something else worth reading. And then: toenail fungus. Yuck.

We talk a lot about good ads appearing next to bad content. Less about bad ads appearing next to good content. Reversed slop, ad slop, "the chumbox". Call it what you want. And no, it’s not an AI phenomenon, it has been around long before. 

And like so many other things in advertising, the initial idea was genuinely good. Seamless, contextual, valuable content. Formats that don't disrupt or disturb. A win-win for publishers, advertisers, and readers alike. If executed right.

The reality became link farms, "you won't believe what happened next", and more photos of toenail fungus than anyone could possibly stomach. And these ads exist in a beautiful arbitrage ecosystem: advertisers pay pennies per click to appear on premium news sites, then send traffic to ad-stuffed landing pages where they make their money back through display advertising.

But before burying the entire format, it's worth making a distinction that not all native is created equal.

Native advertising, done well, is genuinely good. Sponsored content that matches the quality of the surrounding editorial. Branded articles that inform rather than ambush. Paid formats that are clearly labelled but don't feel like a betrayal of the page they're sitting on. It exists and works. The problem isn't native advertising.

The problem is recommendation widgets. They optimise for one thing: clicks. Not quality. Not relevance. Not reader experience. Clicks. Because clicks generate revenue, and the business model rewards whatever gets clicked, which turns out to be outrage, curiosity gaps, miracle cures, celebrity gossip and, yes, toenail fungus.

As Theron Tingstad, CEO of Arbor Growth, described it: the imagery is entirely intentional. Viscous liquids and unsettling textures trigger what he calls disgust-fascination. Your brain can’t look away from something that feels vaguely threatening. AI-generated celebrity faces exploit facial recognition without the copyright liability. Plausible deniability meets engagement bait.

Like with every format, the issue isn't the idea. It's how it's executed. And recommendation widgets, structurally, are optimised to execute it badly.

This isn't entirely new territory. Print magazines and newspapers had their own version, the back pages, the classifieds, the miracle cure patches, the "earn money from home" ads. Low quality, low cost, clearly separated from the editorial content. They knew their place. The reader had to flip to the back to find them. The internet moved the back page to the bottom of the front page. The separation that print maintained by design disappeared entirely. That ad slop that used to live at the back of the magazine now lives underneath every article, on every page, including the best ones. Meanwhile on mobile (the "year of mobile" being fifteen years old), the yuck ads deliver an especially exquisite experience. The bottom of a quality article on a phone screen, is half text, half fungus. In your face. Unavoidable. On a screen where there's nowhere else to look. As if the desktop version isn’t bad enough...

The widget companies didn’t sneak onto the page. They were invited in by publishers who made a choice. The widget revenue share is attractive, the integration is easy, and the reader experience is someone else’s problem. The excuse: we’ll maintain editorial integrity above the fold, but below? Below is the wasteland. There’s a German expression "Ist der Ruf erst ruiniert, lebt es sich ganz ungeniert", roughly: if the reputation’s gone, why hold back. Native advertising fully embraced that. The format didn’t just fall into the gutter, it comfortably settled in there. A(nother) reputation problem the industry didn't fight…just leaned into.

Yes, revenue pressure is real. Publishers are facing shrinking ad budgets, platform dependency, AI eating their traffic and a dozen other existential problems. But scaring off the readers who actually made it to the end of your article with a wall of yuck is hardly the solution. It's the 101 of how to lose a reader in seconds. Because before facing another toenail, most readers will close the tab, close the app, and never come back.

You can’t sell premium and serve ad slop simultaneously. The same publishers running waste at the bottom of every page are also spending significant energy trying to attract premium advertisers. Brand safety certifications, attention metrics, first-party data strategies. Direct sales teams pitching brand-suitable, premium environments.

Brand safety blocklists are already doing significant damage to quality journalism, blocking legitimate news content because an algorithm flagged "shoot" in a sports match report, or "conflict" in a geopolitical piece. Publishers have been fighting that battle for years, with good reason. Meanwhile, on the sell side, they’re serving content that would make even the most permissive brand safety tool nervous. You can’t argue that your editorial environment deserves premium treatment above the fold while running ad slop below it. Advertisers notice when a brand appears three scrolls above the fungus. On the same page. And the halo effect works both ways: a premium environment isn’t just about what’s next to the ad. It’s about everything on the page.

So, do these ads appear on high quality sites? Yes. Do they capture attention? Yes. Do they get clicked? Yes. Are they worth it? Ask the reader who just closed the tab.