Of all web analytics metrics, Bounce Rate is perhaps the most universally applicable. Why? Because, unlike the widely-quoted Conversion Rate metric, Bounce Rate doesn't require you to have defined conversion goals. This means you can use it to understand how well virtually any kind of site performs from a marketing standpoint.
If your site conversion rates are low, Bounce Rate can help you understand why. If your Bounce Rates are also low, your troubles are likely due to site design and usability issues. In this case, you might focus your efforts on streamlining your conversion funnel or making your site easier to navigate. But if your Bounce Rates are high, you can focus your efforts on redesigning entrance (landing pages), improving the quality of traffic to your site, and doing a better job of pairing landing pages with ads.
Our own Avinash Kaushik has just written an excellent article on Bounce Rates in MarketingProfs: Daily Fix. It's appropriately titled Bounce Rate: Sexiest Web Metric Ever?
