The Inventory is Dark and Full of Misinformation: Understanding the Abuse of Ad Inventory Pooling in the Ad-Tech Supply Chain

TL;DR

This paper uncovers how misinformation sites exploit ad inventory pooling in the ad-tech supply chain to deceive brands, highlighting the need for improved transparency and auditing to combat such practices.

Contribution

It is the first study to analyze how misinformation sites subvert ad-tech transparency by pooling inventory, revealing major ad exchanges involved and proposing countermeasures.

Findings

Major ad exchanges are responsible for dark pools exploited by misinformation sites.

Dark pooling enables deceptive ad sales to reputable brands.

Recommendations include better vetting, transparency standards, and independent audits.

Abstract

Ad-tech enables publishers to programmatically sell their ad inventory to millions of demand partners through a complex supply chain. Bogus or low quality publishers can exploit the opaque nature of the ad-tech to deceptively monetize their ad inventory. In this paper, we investigate for the first time how misinformation sites subvert the ad-tech transparency standards and pool their ad inventory with unrelated sites to circumvent brand safety protections. We find that a few major ad exchanges are disproportionately responsible for the dark pools that are exploited by misinformation websites. We further find evidence that dark pooling allows misinformation sites to deceptively sell their ad inventory to reputable brands. We conclude with a discussion of potential countermeasures such as better vetting of ad exchange partners, adoption of new ad-tech transparency standards that enable end-to-end validation of the ad-tech supply chain, as well as widespread deployment of independent audits like ours.