A bounce rate basically means someone was attracted to your site initially because they found one  or two of your keywords and decided to jump on your site. Once they got there they did not really find exactly what they were searching for so they decided to go somewhere else in about…. Two seconds. They hopped off your site so fast that they never really gave your site a once over.

Just like that, in a flash, you have lost a prospect to someone else.

You can avoid this type of thing by getting REALLY TIGHT with your keywords so your online viewer can get a better idea of what your site is all about. By getting much tighter keyword phrases and including them in key areas of your site you can dramatically change the online experience between you and your prospect. You have the control to make it a better experience for all involved.
Let’s hear the definition from the experts….

“A bounce occurs when a web site visitor leaves a page or a site without visiting any other pages before a specified session-timeout occurs. There is no industry-standard minimum or maximum time by which a visitor must leave in order for a bounce to occur. Rather, this is determined by the session timeout of the analytics tracking software.”

A visitor can bounce by:

• Clicking on a link to a page on a different web site
• Closing an open window or tab
• Typing a new URL
• Clicking the "Back" button to leave the site
• Session timeout

Source: Wikipedia

This article goes on to say….

Google.Com analytics specialist Avinash Kaushik has stated:
"It is really hard to get a bounce rate under 20%, anything over 35% is cause for concern, 50%
(above) is worrying."

Here is what they’re talking about…..

The goal here is to give people what they want, as well as eliminate what they don’t want and get them to stay a lot longer.