This paper presents a novel game-like advertising system called GameSense, which is driven by the compelling contents of online images. Given a Web page which typically contains images, GameSense is able to select suitable images to create online in-image games for advertising. The contextually relevant ads (i.e., product logos) are embedded at appropriate positions within the online games. The ads are selected based on not only textual relevance but also visual content similarity. The game is able to provide viewers rich experience and thus promote the embedded ads to provide more effective advertising. Categories and Subject Descriptors H.3.5 [Information Storage and Retrieval]: Online Information Services—Web-based services General Terms Algorithms, Experimentation, Human Factors. Keywords Image advertising, online game.