Driving highly-targeted traffic to your website can be a time-consuming and costly process, so the last thing you want to do is cause your visitors to quickly leave your website, especially if it is due to something that could have been easily prevented, such as these things.
1. Slow load time. Have you ever landed on a website and just sat there waiting … and waiting … and waiting some more for the page to load? It is extremely frustrating, and you probably never returned to that website again because of that horrible experience.
According to KISSmetrics, 47 percent of consumers expect a web page to load in 2 seconds or less, and 40 percent of people abandon a website that takes more than 3 seconds to load.
How to fix it: Run a Google PageSpeed Insights report and GTmetrix performance report for your website. These free tools not only give you a score and grade, but they also provide suggestions to help you improve the speed and performance of your website.
Reference : http://www.entrepreneur.com/article/236548