Bounce Rate essentially represents a measure of website attractiveness. It measures the percentage of initial visitors to a website who 'bounce' away to a different site, rather than continue on to other pages within the same site.

This indicator is included in the book: Key Performance Indicators - the 75+ measures every manager needs to know, which contains an in-depth description of this KPI, as well as practical advice on data collection, calculations, target setting, and actual usage.