The Referral Sources module allows you to ask your users “Where did you hear about us?” anywhere on your site, and track that data in a central location. It provides a admin interface for creating referral sources that users can select from a list, and a page where you can view statistics on referral source selections. Referral source submissions are stored in a single table, no matter where they came from, making it easy to track submissions and create reports based on that data.