I would say that I'm happy to see you here but how can I be sure that you are here? In fact, how do I even know that you are you? Furthermore, how do you know you are you? And, if I were to welcome you, how do I know that I'm me. How do you know that I'm me?
To be on the safe side of things I'll just say that a potential being called "I'm" welcomes a potential being called "you" to this site...
Wait a minute! How do we know that this really is a site?
And if it is, how do we know that "you" are welcome?!
So here goes:
A potential being called "I'm" might welcome a potential being called "you" to a place that just could be a "site".