Understanding the network and user-targeting properties of web advertising networks

Advertising has become an integral and inseparable part of the World Wide Web. However, neither public auditing nor monitoring mechanisms still exist in this emerging area. In this paper, we present our initial efforts on building a network-and content-level auditing service for Web-based ad networks. Our network-level measurements - charting the network infrastructure and quantifying the ad platforms'delay performance - can help commissioners to evaluate their networks from end users'perspective, and let advertisers choose commissioners that better fit their needs. Our content-level measurements - understanding the ad distribution mechanisms and evaluating location-based and behavioral targeting approaches - bring useful auditing information to all entities involved in the online advertising business. We extensively evaluate Google's, AOL's, and Adblade's ad networks and demonstrate how their different design philosophies dominantly affect their performance at both network and content levels.