The study aimed to demonstrate the potential of Google Analytics as a process evaluation method for Internet-delivered interventions, using a website about sexual health as an example. This study reports visitors' behavior until 21 months after the release of the website (March 2009-December 2010). In total, there were 850 895 visitors with an average total visiting time (i.e. dose) of 5:07 min. Google Analytics provided data to answer three key questions in terms of process evaluation of an Internet-delivered intervention: (i) How do visitors behave?; (ii) Where do visitors come from? and (iii) What content are visitors exposed to? This real-life example demonstrated the potential of Google Analytics as a method to be used in a process evaluation of Internet-delivered interventions. This is highly relevant given the current expansion of these interventions within the field of health promotion.