很多時候廠商手上握有的資訊會比消費者多，使得消費者在購買產品後，發現產品不如預期的情況下，消費者往往只能理虧，求助無門。因此在1970年代提出資訊不對稱的概念後，信息理論的重要性就逐漸提升，目的是要解決廠商手上握有資訊比消費者多的逆向選擇問題。
其中，又以成本風險類的信息與消費者息息相關，例如保證型態的信號，目的是透過售後退款的方式，補足消費者對於購買產品的不確定性。然而近年來，健身產業的消費糾紛層出不窮，例如全台灣最大的健身俱樂部World Gym 在2014年產生610件的退費糾紛。此類的負面新聞會提升消費者對於損失的外在財務風險以及內在情感的社會風險。
接著有學者提出進階的服務保證概念，是希望透過不同類型的服務保證，將服務的抽象概念，以具體化的形式，在公司無法承諾消費者當初的約定時，給予獲補償消費者的方式。其中何種服務保證類型最為有效降低消費者的知覺風險，便是本議題欲探討之處。而隨著手持裝置的興起，口碑等外在因素的干擾便也逐漸成為廠商和消費者所關注的重要因素。
因此，本研究以健身方案為例，以實驗設計法，探討三種服務保證類型和正負面口碑，組合而成的六種情境組合，延伸探討廠商提供的何種服務保證類型最能有效降低消費者的知覺風險(財務風險、社會風險)進而提升購買意願。
研究結果顯示，以健身方案為產品中，廠商若提供無條件服務保證最為有效的降低消費者的知覺風險(財務風險、社會風險)。此外，在口碑效果會強化無條件服務保證降低消費者知覺風險(財務風險)的效果，並且能顯著提升消費者參與健身方案的意願。因此廠商未來目的為增加利潤的情況下，善用口碑策略，就能有效吸引消費者加入。
關鍵字:資訊不對稱、服務保證、知覺風險、口碑、購買意願

The main objective of this study is to investigate whether service guarantee affects consumer perceived risk related to purchasing an exercise project in information asymmetric surroundings. In addition to the main objective of this study, we plan to further investigate which service guarantee type consumers will prefer when purchasing an exercise project. Six scenarios were created in this experimental design to test the effect on three types of service guarantees and two different types of word of mouth. In this study, SPSS 22 was used to run a factor analysis, a regression analysis and an analysis of variance for the purpose of statistical analysis. According to the data analyses, there are some conclusions and implications to consider:

1. Service guarantees significantly decrease the effect on consumer perceived risk, indicating that it can significantly increase exercise project purchasing intention.
2. An unconditional service guarantee has the best influence on decreasing consumer perceived risk as compared to other types of service guarantees. This finding indicates that if consumers engage in an exercise project, they prefer the project which contained completely compensate mechanism.
3. Word-of-mouth was found to significantly moderate the effect between the unconditional service guarantee and perceived risk. This finding indicates that as long as a company uses social media well, it will generate better influence on its unconditional service guarantee.

These conclusions implicate that in the exercise industry, consumers focus on unconditional service guarantees for exercise projects to decrease perceived risk and suggest that firms can use word-of-mouth to generate higher decreases in consumer perceived risk.

Key words: information asymmetry, service guarantee, word of mouth, perceived risk, purchase intention

一、 中文文獻
2014/12/22-DIGITIMES企劃
DIGITIMES中文網 原文網址: 零售4.0 運用科技優化消費體驗 http://www.digitimes.com.tw/tw/dt/n/shwnws.asp?cnlid=13&id=0000405419_SA55VEP90PQEFOLEPNT0A&ct=1#ixzz3aYSrHjLJ
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