Exploring the Cookieverse: A Multi-Perspective Analysis of Web Cookies

TL;DR

This study provides a comprehensive analysis of web cookies across different geographic locations, device types, and banner interactions, revealing significant variations and emphasizing the importance of multi-perspective approaches in web measurement research.

Contribution

The paper introduces BannerClick, a highly accurate tool for detecting and interacting with cookie banners, and offers a multi-perspective analysis of cookie deployment across various factors.

Findings

Cookies are 56% more prevalent in the EU region.

Accepting cookies increases third-party cookies by 5.5x.

Banner interaction significantly impacts cookie types and counts.

Abstract

Web cookies have been the subject of many research studies over the last few years. However, most existing research does not consider multiple crucial perspectives that can influence the cookie landscape, such as the client's location, the impact of cookie banner interaction, and from which operating system a website is being visited. In this paper, we conduct a comprehensive measurement study to analyze the cookie landscape for Tranco top-10k websites from different geographic locations and analyze multiple different perspectives. One important factor which influences cookies is the use of cookie banners. We develop a tool, BannerClick, to automatically detect, accept, and reject cookie banners with an accuracy of 99%, 97%, and 87%, respectively. We find banners to be 56% more prevalent when visiting websites from within the EU region. Moreover, we analyze the effect of banner interaction on different types of cookies (i.e., first-party, third-party, and tracking). For instance, we observe that websites send, on average, 5.5x more third-party cookies after clicking ``accept'', underlining that it is critical to interact with banners when performing Web measurements. Additionally, we analyze statistical consistency, evaluate the widespread deployment of consent management platforms, compare landing to inner pages, and assess the impact of visiting a website on a desktop compared to a mobile phone. Our study highlights that all of these factors substantially impact the cookie landscape, and thus a multi-perspective approach should be taken when performing Web measurement studies.