Due to enormous competition on the Web, usability is a vital surviving factor. If a website is difficult to use, people turn to your competitors. It's that simple. Here are some other reasons why visitors leave:
- The homepage fails to communicate what you offer and what problem you solve
- They can't easily navigate the website or web app
- They don't understand where they are
- They can't quickly get what they need
- They are forced to watch a boring presentation
- They see irrelevant links to other websites
- They need to use magnifying glass to read they text
- They need to install a plug in to see your content etc...
Visitors never spend time trying to figure out the interface of your site. They don't read manuals and they don't contact support. They just go to another website that "just works" and never come back.