Over the last ten years the Internet has become an incredibly important media in everyday life of ordinary people. By now the World Wide Web is not a foreign concept anymore; millions of people make use of the internet in terms of e-mail, online banking, online shops, etc. Companies have realised the necessity of user friendly interfaces and software which even an inexperienced user is able to handle. Since the interaction with the Internet becomes ubiquitous, assessing usability of interfaces is a fundamental and necessary part of HCI development. Observing the overt behaviour of users, (which button does a user click on, how is the mouse used), retrospective self report, questionnaires and thinking aloud methods are just examples of traditional and quite successful strategies in order to investigate usability problems. So, why should there be a need for a new method when conventional methods seem sufficient in optimising usability and what is it’s contribution in the evaluation of how usable a particular design is? We will give a short introduction of the eye tracking method in applied marketing research and its benefits. Reporting two of our studies we will discuss the limits of traditional usability testing and will show how tracking the eye gaze can fill this gap.