The literature considers the virtual communities as a group of reference. This explanatory study looked to investigate the relationship among the members of these communities and the influence that the groups exercise on the purchase decisions of its members. The research was divided into two parts: initially the comments of the community members, chosen as an object of study, were analyzed to indentify categories related to the influences. Following that, 21 participants were interviewed from a detailed outline based on identified categories. The analysis of the messages posted in the group and of the interviews showed evidence of an existing code of behavior, suggesting that for some members, the community acts as a normative reference group, characterized by strong identification among the participants. The group leaders seem to participate the most in the debates, or the ones who already had experiences with a range of products and services related to the subject of the group, or the ones who are believed to have good taste. Besides everything that was said, changes in choices and behavior were also observed, as a result of the interactions among the participants.