tedster - 7:21 pm on Mar 1, 2011 (gmt 0)
I think it's a good metric for the webmaster, especially in A/B testing and the like. It's just terrible for ranking search results. If a webmaster has more than one site, they can't even compare one directly to the other. It takes intimate knowledge on a page-by-page basis to get actionable intelligence. No algorithm uses that kind of knowledge.