Why Listening to Users Can Damage Your Website
The first time I noticed that people tend to say one thing and do another in a usability test was back in 2000. We had been building a new company website and testing it with real users brought us an unexpected problem. All the users liked the new design a lot more than the old one, but nobody could work out how to use it.
Unsworth, David. Usability Professionals Association (2005). Articles>Web Design>Usability