全球行動電話普及率逐年上升，行動電話已經成為人們生活中不可或缺的通訊與傳播工具。根據國家通訊傳播委員會(National Communications Commission, NCC)提供的資料顯示，目前台灣地區行動電話用戶數為2,399萬戶，手機門號人口普及率為104.6%，其中3G用戶已超過590萬戶，行動數據加值服務普及率應有顯著地成長，然而根據資策會FIND(Foreseeing Innovative New Digiservices)調查顯示，台灣地區行動數據服務營收占ARPU(Average Revenue Per User：平均每戶營收)的比例僅有8.3%。另一方面，在NCC要求語音及簡訊費用調降的政策下，國內行動通訊服務業者勢必加速深耕3G加值服務內容的布局，以有效提升ARPU的比例。故本研究以3G加值服務為研究主題，並藉此了解國內消費者對於3G加值服務之態度及採用的行為意圖。
本研究以科技接受模式為理論基礎，結合創新擴散理論、知覺有趣與知覺風險，建構一個延伸的科技接受模式，希冀對消費者採用3G加值服務之行為意圖有更深入之探究。經網路問卷調查，共回收342份有效問卷，以結構方程模式進行分析後，本研究之重要實證結果如下：(1)「知覺易用」對於「知覺有用」和「知覺有趣」有直接且非常顯著的正向影響關係。(2)「使用態度」乃是直接決定「行為意圖」之最重要因素，亦即消費者對於3G加值服務之態度若愈正向，則其採用3G加值服務的意願就會更高。故行動通訊業者應著力於消費者使用態度之提升，而使用態度之提升則有賴於「知覺有趣」、「可觀察性」與「相容性」的直接強化。(3)「知覺風險」對於「行為意圖」有顯著的負面影響關係，即消費者知覺到使用3G加值服務之風險性愈高，會降低使用3G加值服務之意願，故這可能也是相關業者要克服的問題之ㄧ。(4)本研究建構之模型對於採用3G加值服務之行為意圖具有可接受之解釋力。

The usage rate of the cell phone has risen year by year in the world, and the cell phone has already become the necessary communication and medium tool in the life. According to the information which the National Communications Commission (NCC) releases demonstrates that currently there are approximate 23,990,000 persons using the cell phone in Taiwan, in which the users adopting the third generation mobile service has surpassed 5,900,000 persons, and the usage rate of the cellular phone number is 104.6%. In theory, that would accompanies the usage rate of the mobile value-added services growing up, however a recent survey of domestic costumers’ behavior doing by Mobile Internet in Taiwan Foreseeing Innovative New Digiservices shows that the mobile digital service revenue occupies the proportion of average revenue per user (ARPU) only has 8.3%. On the other hand, under the policy which the NCC requests the related operators to decrease the voice and message service price, the domestic mobile service operators certainly should make great effort to improve the third generation value-added services and effectively rise the proportion of ARPU. Therefore this research takes the third generation value-added service as the research subject, and intents to realize consumers’ attitude and behavioral intension about adopting the third generation value-added services.
This study takes the technology acceptance model (TAM) as basis and combines the five characteristics of the innovation diffusion theory (IDT), perceived enjoyment, and perceived risk to construct an extended TAM to understand the consumers' behavioral intention about adopting the third generation value-added services. After survey by questionnaire and analyze the data by structural equation modeling, we get such points: (1) Perceived ease of use has very significant directly and positive influence on perceived usefulness and on perceived enjoyment. (2) Attitude is positively associated with behavioral intention. If the mobile service operators try to make consumers have positive attitude with the third generation value-added services, they should primarily emphasize on perceived enjoyment, observability, and compatibility in turn. (3) Perceived risk has significant negative effect on behavioral intention. So reducing the uncertain risk when customers are consuming is one of the problems that mobile service operators should overcome. (4)The proposed model has confidant explanation to the consumers' behavioral intention about adopting the third generation value-added services.

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