Big Tech’s inadequate ad transparency: researchers find X is the worst

If you want to know who paid for an ad online and what it advertises, prepare to scroll through the endless CSV file, which takes 10 minutes to load in the worst case. And there is no best case, as all big tech platforms offer ad transparency tools that have big gaps in data and functionality.

Half a year has passed since the EU introduced the Digital Services Act, which requires big tech companies to have ad repositories.

Mozilla, together with disinformation research company CheckFirst, scrutinized ad libraries in a series of stress tests to find out that none of them are fully functional, effective, easy to use, or compatible. They are often hard to find.

“We find a huge variation among the platforms, but one thing is true across all of them: none is a fully functional ad repository, and none will provide researchers and civil society groups with the tools and data they need to effectively monitor the impact of very large online platforms and search engines advertisements on Europe’s upcoming elections,” the report reads.

AliExpress’s repository provided minimum data transparency, had no API, a very minimal user interface, and even required a user account to access. Researchers encountered loading and display errors and were blocked several times by anti-bot tools. And that was not the worst.

“X (formerly Twitter) only provides a CSV file,” researchers noted. “While these platforms provide the worst examples, we struggle to tell you which one is best.”

The testing was conducted between December 2023 and January 2024 and included 11 big platforms. None of them were evaluated as “ready for action.”

TikTok, Meta, LinkedIn, and Apple App Store were evaluated as still having big gaps in data and functionality. Alphabet, Booking.com, and Pinterest got the evaluation of “bare minimum data and functionality.

In red territory were Zalando, X, SnapChat, Bing, and Aliexpress, receiving the evaluation “Lacks vital data and functionality.”

Tests were designed to evaluate the robustness, reliability, and effectiveness of the ad repositories under various conditions and loads to mimic real-world demands and challenges. Usability testing aimed to ensure that the ad repositories are also user-centric, the report explains.

Researchers shared many recommendations for platforms and regulators. Mozilla thinks the European Commission and the Board for Digital Services Coordinators should develop guidelines on ad repositories in consultation with the research community.

There’s also a lack of standardization of APIs across big tech to increase usability and facilitate cross-platform research. Disclosure requirements should be strengthened for branded or “influencer” content.

Platforms still have to remove many access barriers, making ad libraries hard to access, adding better documentation and user support, and harmonizing APIs.

“Repositories should provide more complete data on ad campaigns and more granular information about ad intentions and effectiveness,” the researchers recommend. “Search functionalities should be improved, with additional options to export data.”

The non-profit organization Mozilla is an internet advocate for privacy, openness, innovation, and opportunity on the internet.

“While these tools are far from perfect, we applaud these companies for getting this far, and we make several recommendations that we hope can be useful for their continued improvement,” Mozilla said in a press release.