The Bounce Rate

The Bounce rate shows the effectiveness of your webpage.

It is the percentage of people/visitors to your website that leaves without looking at the content pages inside the site. They are just looking at the first page - The Landing Page - and then they leave.

"Imagine looking down a busy street, You don´t see all the Toyotas, but if a Ferrari comes along, You have a second look"

Some say your bounce rate should be below 50% but it depends a lot on what kind of site you have - Sales page, blog - Blogs normally has a higher rate of bounces as most visitors are reading the latest content blog post and then leave.

A way of tracking and analyzing your bounce effectiveness is to use the Google Analytics program and yes it´s Free!

More sources:
http://www.google.com/support/analytics/bin/answer.py?hl=en&answer=81986
http://en.wikipedia.org/wiki/Bounce_Rate
http://www.hmtweb.com/blog/2007/08/bounce-rate-and-exit-rate-what-is.html
http://www.kaushik.net/avinash/2007/05/excellent-analytics-tip-11-measure-effectiveness-of-your-web-pages.html