it does not include any cookie by which your browser history can be tracked [3].
Umm, it involves a cookie, which tracks whether you have previously browsed the site. While I applaud the analytics team in using such a privacy friendly method, I'm not sure its an entirely truthful statement to say that it does not involve a cookie in which your browser history can be tracked. The date you've visited previously sounds like a part of your browser history to me.
To be clear, this is not meant to be a criticism. I think the approach that is being taken is really great.
-- -bawolff