You don’t need separate AdRoll pixels for subdomains. AdRoll uses a single universal pixel that can track activity across your main domain and its subdomains. When setting up your campaigns, ensure that the universal pixel is properly installed on all pages, including those on subdomains. This allows AdRoll to track visitors seamlessly, regardless of which subdomain they visit. If you want to segment data by subdomain, you can do so within your AdRoll dashboard by setting up audience rules. This setup makes it easy to manage campaigns without the hassle of adding multiple pixels.