JesterMagic - 2:51 pm on Apr 16, 2013 (gmt 0)
visitor behavior (completely in my opinion) is becoming, or has become, the "new links" in rankings.
What really is good visitor behavior though? Say a person only visits one page of your site and leaves. This could be a good thing if he found the information they was looking for, or a bad thing if he didn't.
Google would have to keep track of what the visitor continues to do (ie if he goes back to search from your page and searches for the same thing again) to even start to figure out if the visitor behavior is positive or negative for the site.