Third-party Service Dependencies and Centralization Around the World

There is a growing concern about consolidation trends in Internet services, with, for instance, a large fraction of popular websites depending on a handful of third-party service providers. In this paper, we report on a large-scale study of third-party dependencies around the world, using vantage points from 50 countries, from all inhabited continents, and regional top-500 popular websites.This broad perspective shows that dependencies vary widely around the world. We find that between 15% and as much as 80% of websites, across all countries, depend on a DNS, CDN or CA third-party provider.Sites critical dependencies, while lower, are equally spread ranging from 9% and 61% (CDN and DNS in China, respectively).Despite this high variability, our results suggest a highly concentrated market of third-party providers: three third-party providers across all countries serve an average of 91.2% and Google, by itself, serves an average of 72% of the surveyed websites. We explore various factors that may help explain the differences and similarities in degrees of third-party dependency across countries, including economic conditions, Internet development, language, and economic trading partners.