Many people point to the bounce rate in Google Analytics and assume that those who bounced are worthless visitors. This is not the case.
Before I explain why, I want to say that I have changed the GA code so that Bounce Rate is calculated from those who spent less than 10 seconds on the site, not those who viewed one page, which is the default. The reason I did this is that many of my sites are blogs or are using blogging extensively. If a visitor enters on a category page, they can spend up to 10 minutes reading posts, yet the default GA code only sees one page viewed, and says that they bounced.
If you would like to use this bounce rate, you need setTimeout, and here the code and where to place it:
var pageTracker = _gat._getTracker(“UA-xxxxx-x”);
setTimeout(‘pageTracker._trackEvent(‘NoBounce’, ‘NoBounce’, ‘Over 10 seconds’)’,10000);
Now, why are visitors who bounce not worthless? Simple, GA seems to be calculating bounces off of the most recent visit. This does not mean that the visitors have not spent time on your site before. Here is a screen shot of the Visitor Loyalty report, segmented by those who bounced.