"In short, usability is the ease with which someone can use your website to do a particular task and get the expected results based on what they currently know,"
"In other words, the site has to be intuitive. Still, many companies are not addressing the usability problem at the level they should to avoid website usability pitfalls."
This one may be ring a bell to website managers ?
"When a site is designed with usability in mind, there is a large drop-off in the need for user training, expensive help desks to answer questions from confused web users, and it drastically reduces the need for future rewrites," Elges says. "In addition, usability noticeably increases the lifespan of your website, since most rewrites are due to poor usability issues."