This document summarizes a study on traveler attribution that analyzed clickstream data to understand how travelers research and book flights and hotels. Some key findings: 1. OTAs are used throughout the travel planning process from inspiration to research to booking. Meta sites are commonly used for research and drive traffic to OTAs. 2. Supplier sites that consumers start their research on see more bookings on those supplier sites, but not always where research began. 3. The study provides recommendations for marketers to take a full-funnel media approach leveraging OTAs and meta sites, create partnerships across influential touchpoints, and give travelers a reason to remember and return to brands.