Understanding Data Collection, Brokerage, and Spam in the Lead Marketing Ecosystem

2026-04-08

AI Summary

This study presents the first empirical measurement of the lead-generation ecosystem in high-value vertical domains such as insurance, uncovering severe privacy violations and spam risks arising from the large-scale collection and resale of users’ sensitive health information. By deploying an end-to-end measurement framework—encompassing monitoring of over 100 health-related lead websites, 200 controlled contact points, and real/simulated lead-purchasing experiments—the research demonstrates that users experience phone harassment within seconds of form submission, receiving over 8,000 calls, 600 text messages, and 200 emails. The investigation identifies data sharing with more than 70 third parties, deceptive practices including fabricated health attributes, widespread failure of opt-out mechanisms, and prevalent neighbor-spoofing tactics. The findings reveal a highly interconnected ecosystem that routinely violates regulatory compliance requirements.

Abstract

The lead marketing ecosystem enables collection, sale, and use of personal data submitted via web forms to deliver personalized quotes in high-value verticals such as insurance. Despite its scale and sensitivity of the collected data, this ecosystem remains largely unexplored by the research community. We present the first empirical study of privacy and spam risks in lead marketing, developing an end-to-end measurement framework to trace data flows from data collection to consumer contact. Our setup instruments over 100 health-related lead-generation websites and monitors 200 controlled phone numbers and email addresses to understand downstream marketing practices. We observe sharing of highly personal and sensitive health information to more than 70 distinct third parties on these lead generation websites. By purchasing our own and other organic leads from three major lead platforms, we uncover deceptive brokerage practices, where consumer data is sold to unvetted buyers and often augmented or fabricated with attributes such as health status and weight. We received a total of over 8,000 telemarketing phone calls, 600 text messages, and 200 emails, where calls often began within seconds of form submission. Many campaigns relied on VoIP-based neighbor spoofing and high-frequency dialing, at times rendering phones unusable. Our experiments with phone and email opt-outs suggest phone-based opt-outs to help the most, although all were ineffective at completely stopping marketing communications. Analysis of 7,432 Better Business Bureau (BBB) complaints and reviews corroborates these findings from the consumer perspective. Overall, our results reveal a highly interconnected and non-compliant lead marketing ecosystem that aggressively monetizes sensitive consumer data.

Problem

• lead marketing
• data privacy
• spam
• data brokerage
• consumer protection

Innovation

• lead marketing ecosystem
• data brokerage
• privacy risks
• spam measurement
• deceptive data practices