Recently, I experienced an unusual phenomenon with Google analytics on a site I redesigned. I noticed after the redesign, my bounce rate went from about 50% to 0.85%. This is way too low for a bounce rate, which at best should hover around 20-30%. At first I was utterly overjoyed that my new design so encouraged visitors to click on other links and interact more.
Pretty soon, however, I realized that while my bounce rate was unreasonably low, my Average Time on Site was about the same. Curious! Digging through the code, I soon realized I made a stupid mistake that falsely made my bounce rate so low: I’d inadvertently included the Google Analytics tracking code both in the header (the old location) and in the footer right above the closing body tag. My mistake! Rectifying this error made my bounce rate return to normal.
Hope this helps someone struggling to comprehend absurdly low bounce rates.