Ads are often designed visually, with images and videos conveying information. In this work, we study the accessibility of ads on the web to users of screen readers. We approach this in two ways: first, we conducted a measurement and analysis of 90 websites over a month, collecting ads and auditing their behavior against a subset of best practices established by the Web Content Accessibility Guidelines (WCAG). Then, to put our measurement findings in context, we interviewed 13 blind participants who navigate the web with a screen reader to understand their experiences with (in)accessible ads. We find that the overall web ad ecosystem is fairly inaccessible in multiple ways: many images are missing alt-text, unlabeled links make it confusing for folks to navigate, and closing ads can be tricky. But, there are straightforward ways to improve: because only a few large companies dominate the ad ecosystem, making small changes to the way they enforce accessibility standards can make a large difference.

Online ads are a major source of information on the web. The mass reach of online advertising is often leveraged for information dissemination, at times with an objective to influence public opinion (e.g., election misinformation). We hypothesized that online advertising, due to its reach and potential, might have been used to spread information around the 2022 Russian invasion of Ukraine. Thus, to understand the online ad ecosystem during this conflict, we conducted a five-month long large-scale measurement study of online advertising in Ukraine, Russia, and the US. We studied advertising trends of ad platforms that delivered ads in Ukraine, Russia, and the US and conducted an in-depth qualitative analysis of the conflict-related ad content. We found that prominent US-based advertisers continued to support Russian websites, and a portion of online ads were used to spread conflict-related information, including protesting the invasion, and spreading awareness, which might have otherwise potentially been censored in Russia.

Abstract Internet advertising and analytics technology companies are increasingly trying to find ways to link behavior across the various devices consumers own. Thiscross-device trackingcan provide a more complete view into a consumer’s behavior and can be valuable for a range of purposes, including ad targeting, research, and conversion attribution. However, consumers may not be aware of how and how often their behavior is tracked across different devices. We designed this study to try to assess what information about cross-device tracking (including data flows and policy disclosures) is observable from the perspective of the end user. Our paper demonstrates how data that is routinely collected and shared online could be used by online third parties to track consumers across devices.