How does this solution work? Is it using the cookies tracking described below by farren? http://news.ycombinator.com/item?id=3994694 http://news.ycombinator.co

How does this solution work? Is it using the cookies tracking described below by farren? http://news.ycombinator.com/item?id=3994694 http://news.ycombinator.com/item?id=3994694