If you have a single business or project that spans multiple websites, Heap can still track users across those domains. For subdomains on the same domain (e.g. “www.example.com”, “blog.example.com”, and “signup.example.com”), Heap will automatically tie together a user’s activity across each subdomain. For separate domains (e.g. “example.com” and “example2.com”), Heap will treat activity from the same user on two different domains as two different users (because of how browser cookies work). In this case, you can use the identify API to bypass this and tie together a user’s activity across different domains.