Jakob Nielsen on Usability Testing

Do you spend one day per week on observing how new users interact with your product? In fact, do you have any usability testing at all in your budget? In the rare event that you do run usability testing sessions, do you focus on actual user behavior (and not waste time by having users fill in endless questionnaires)? If you tend to answer "no" to these questions, read Jakob Nielsen's article on how to properly conduct usability testing sessions.