By not adding it to your site, you could be cutting off users who would use it. By adding it to your site, maybe no one will use it, but its there if someone wants to. So adding it can't hurt.
As for being a pain to update - just write a script that automatically updates it.
Here are some sites that I found on google. Haven't looked through them, but they seem to fit the bill of what you are looking for:
RSS Statistics
RSS Statistics