App 內購買(In-App Purchase, IAP)已成為現今App 營收的主要模式，而過 去針對此一現象的研究大多集中於遊戲類的App，較少針對其他類型App(工 具、資訊、社交)進行探討。 本研究先利用文獻歸納的方式，整理出可能影響使用者App 內購買的因 素，再透過深度訪談法，針對曾經進行過App 內購買的使用者進行訪問，歸納 出App 使用動機、販售商品與App 的互補性與口碑情緒三個因素會影響使用者 對商品的知覺價值與購買意圖，並依此建構本研究的研究模型，並進行實驗設 計。在實驗中，本研究挑出四種不同類型的App，並以高低互補性、正面口碑 的有無為操弄變項，搭配App 使用動機來搜集資料並進行分析。 研究結果發現：(1) 部分App 使用動機會對知覺價值與購買意圖有顯著影響。 (2) App 與商品的互補性對於知覺價值與購買意圖皆有顯著影響。(3) 口碑對於 商品的知覺價值有顯著影響，但是對於購買意圖沒有顯著影響。顯示IAP 商品 是否能與App 有效整合，為App 帶來更多的價值，才是影響使用者購買意圖的 最大因素。 / In-App purchase(IAP) has become the main revenue model in App market. Previous studies on this issue are mostly focused on game Apps, and rarely explored other types of Apps such as productivity tools, information or social networking tools. In this study, we use literature analysis and in-depth interviews to find factors that may affect users’ in-app purchase intention. User motivation, product complementarity, and word-of-mouth are found to affect users’ perceived value and in-app purchase intention. We developed a theoretical model and designed an experiment to test the model. In the experiment, we chose four different types of Apps, designed with different levels of complementarity and different sentiment of word-of-mouth (user comments) as the treatment. The results indicated that: (1) Certain motivations significantly affected the perceived value and purchase intention of IAP products. (2) Complementarity between IAP products and the App significantly affected the perceived value and purchase intentions of IAP product. (3) word-of-mouth significantly affected perceived value but not affecting the purchase intention of IAP products.