If it's your own domain it will be a verification that you actually have access to it, if it's from a random website it's just a normal username people can search you with, instead of an npub  

 Oh, so it's more to verify my domain. Seems like users can still search for me via name tho and not just npub... 🤔 

 They can but there can be multiple nouns with your name, which one is you?  

 Npubs* there can only be 1 person with a nip05 identifier