mslina2002 - 3:34 am on Jun 26, 2012 (gmt 0)

I think that time spent searching after one leaves the site is also an important factor and which we don't have any metrics for except for Goog.

If visitors repeated continue searching after leaving your page, is a clear indication that user experience was poor. So there must be some comparison done between sites with similar niches to see which sites have a low search rate after visitors exit.