Measuring third party tracker power across web and mobile

TL;DR

This paper introduces a novel method to measure the power of third-party trackers across web and mobile platforms by assessing their reach on popular sites and apps, revealing significant influence of tracker prominence and corporate relationships.

Contribution

It presents a new approach to quantify tracker concentration based on reach, addressing limitations of traditional market share metrics across web and mobile.

Findings

Tracker prominence significantly affects measurement accuracy

Parent-subsidiary relationships influence tracker power assessment

Reach-based metrics provide a better understanding of tracker influence

Abstract

Third-party networks collect vast amounts of data about users via web sites and mobile applications. Consolidations among tracker companies can significantly increase their individual tracking capabilities, prompting scrutiny by competition regulators. Traditional measures of market share, based on revenue or sales, fail to represent the tracking capability of a tracker, especially if it spans both web and mobile. This paper proposes a new approach to measure the concentration of tracking capability, based on the reach of a tracker on popular websites and apps. Our results reveal that tracker prominence and parent-subsidiary relationships have significant impact on accurately measuring concentration.