Thousands of websites are quietly fighting ad blocking

Just because you can't see it doesn't mean it isn't happening.

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Websites aren't always conspicuous in their attempts to combat ad blockers. Researchers from the University of Iowa and UC Riverside have learned that 30.5 percent of the top 10,000 websites have measures to thwart ad blocking, and they're frequently using methods you wouldn't likely notice. Many use scripts to introduce 'bait' content that sets off ad blockers, prompting the site to relaunch ads in a way that blockers might not catch.

Previous estimates had acknowledged that these surreptitious methods were in use, but on no more than 5 percent of big sites. The data suggests that this is far more common.

There are ways for ad blockers to play cat-and-mouse: they can change their Javascript to fool anti-ad-blocking systems, or even detect bait material and refuse to block it. However, the discovery hints that there could be a mounting "arms race" where ad-dependent websites and ad blockers continuously try to one-up each other. That's not necessarily a bad thing -- while it could starve some sites of needed revenue, it might also discourage others from implementing annoying ads.