YouGov Profiles is a tool that allows users to profile audiences across various data sets from YouGov surveys to better understand demographics, interests, and behaviors. It provides information on over 200,000 variables for 250,000 panelists. The document describes a case study on ASOS customers and their attributes. It also discusses expanding Profiles to new international markets and introducing new features like dynamic segmentation and re-contact surveys. BrandIndex is mentioned as a complementary tool that tracks brand metrics over time.