Achieving social welfare and success is heavily reliant on our ability to persuade and influence others, yet this capacity is known to be one of the most challenging social skills to develop and possess. With social networking websites becoming a crucial platform for routine social activities, gaining insight into the strategies and mechanisms behind online persuasion is of great interest and value to a variety of disciplines. Hence, in this study, we aim to study written comments in online deliberations and understand what makes people change their beliefs. We explore different dimensions of the language, the order of the comments, as well as the attributes of the participating users and their relation to the persuasion process. In addition, we investigate the factors that persuaded users (the ones who have already changed their beliefs) perceived to be the reasons that led to their opinion change. We link our findings to earlier research on persuasion and belief change in traditional forms, hoping to uncover when and how they apply to online persuasion.