Adscape: Harvesting and Analyzing Online Display Ads

TL;DR

This study systematically analyzes online display ads by developing a scalable crawler to collect over 175,000 ads, revealing insights into targeting mechanisms, advertiser diversity, and profile-based ad variation.

Contribution

It introduces a novel scalable crawling approach to analyze display ads and provides comprehensive insights into ad targeting, diversity, and user profile influence.

Findings

Ads vary more over user profiles than websites.

Targeting is widely used but not universal.

Identified over 3,700 distinct advertisers.

Abstract

Over the past decade, advertising has emerged as the primary source of revenue for many web sites and apps. In this paper we report a first-of-its-kind study that seeks to broadly understand the features, mechanisms and dynamics of display advertising on the web - i.e., the Adscape. Our study takes the perspective of users who are the targets of display ads shown on web sites. We develop a scalable crawling capability that enables us to gather the details of display ads including creatives and landing pages. Our crawling strategy is focused on maximizing the number of unique ads harvested. Of critical importance to our study is the recognition that a user's profile (i.e. browser profile and cookies) can have a significant impact on which ads are shown. We deploy our crawler over a variety of websites and profiles and this yields over 175K distinct display ads. We find that while targeting is widely used, there remain many instances in which delivered ads do not depend on user profile; further, ads vary more over user profiles than over websites. We also assess the population of advertisers seen and identify over 3.7K distinct entities from a variety of business segments. Finally, we find that when targeting is used, the specific types of ads delivered generally correspond with the details of user profiles, and also on users' patterns of visit.