Marketing a brand and analyzing the effectiveness of promotional campaigns have always been major topics for marketing. In today's world, marketers use many data sources to analyze the behavior and responses of their consumers. This mainly involves data from Point of Sales, consumer surveys or home visits. However, with the advancement of web technologies, there is one more place where data is available: User generated content (UGC) from Web 2.0 applications. The purpose of this conceptual paper is to formulate hypotheses for the interrelationship between user generated content on the Internet and brand marketing and promotional effectiveness of a firm or campaign.