A recent study has revealed that around 10% of websites, which purportedly adhere to the Acceptable Ads Standard, are in fact displaying non-compliant ads. These findings indicate potential flaws in the ad-filtering rules used by browser extensions. The research suggests that these tools may be vulnerable to exploitation by advertisers seeking to display non-compliant ads.
Online advertising plays a crucial role in supporting many websites financially. However, such ads sometimes negatively impact user experience, disrupt browsing with intrusive elements, and risk user privacy by collecting data without consent.
In response to these issues, a group of stakeholders, including advertisers, ad-tech providers, and content creators, established standards in 2011 known as the Acceptable Ads Standard. This initiative aimed to balance the needs for ad revenue and user concerns. Ads complying with these standards are typically not blocked by most ad blockers.
Ahsan Zafar, a Ph.D. student at North Carolina State University and the study’s first author, noted, “I have some familiarity with the Acceptable Ads Standard, and I continued to see ads that seemed to violate the standard on sites that were purportedly in compliance.” This observation led to questions about whether these sites were actually compliant and the presence of potentially non-compliant ads.
The researchers investigated the top 10,000 websites adhering to the Acceptable Ads Standard, according to Tranco’s “top 100K” list, to check for non-compliant ads.
Using a custom webcrawler, they discovered that 991 sites (about 9.91%) displayed at least one ad violating the Acceptable Ads Standard. According to Zafar, “We found that oversized ads and overlay ads – which covered up some of the content – were the most frequent violators.”
Anupam Das, senior author and assistant professor of computer science at NC State, noted that these ads evaded detection due to design flaws in ad-blocking software. “The fact that these ads were not blocked tells us there are design flaws that allow ad creators to bypass size and format restrictions,” Das explained.
Some ad creators might unknowingly produce non-compliant ads, but others might exploit known loopholes, the researchers suggest. Zafar notes, “After investigating how these ads could be slipping through, we found that some of the rules used by ad-blocking extensions to determine Ads Standard compliance are simply too permissive or too general.”
The team proposed changes to the compliance rules, resulting in a 32% increase in previously noncompliant websites meeting standards. However, these revisions also inadvertently increased the number of compliant ads blocked.
“This was preliminary, proof-of-concept work,” Das remarked. The team is working on refining these rules further to minimize noncompliance without affecting compliant ads negatively.
The research, titled “Assessing Compliance in Digital Advertising: A Deep Dive into Acceptable Ads Standards,” is set to be presented on May 1 at the ACM Web Conference in Sydney, supported by the National Science Foundation under grant number CNS-2138138.
