Especially for public facing portions of websites (e.g. blogs), it would be really nice if Confluence allowed anonymous users to optionally enter their name, email, and/or website when providing a comment (similar to WordPress and various other blogging products).

This would provide a structured means of identifying who is making the comment and a way to communicate back with the commenter without eating up a user license.

Another alternative, albeit more radical, would be to enable some sort of "commenter only registration" that would create a confluence user account that would only have the ability to comment on anonymously accessible pages, but which wouldn't consume a user license (although there should be an admin interface to selectively "promote" these users to fully licensed users if desired).

The bottom line is that if a website is going to expose a blog to the internet, they shouldn't be forced to purchase an unlimited user license just to allow blog commenters to identify themselves.