本研究以從眾行為觀點探討青少年集點換購贈品之購買決策因素。經由相關文獻探討論彙整並透過德爾菲法、層級分析法來了解青少年之從眾行為對於7-ELEVEn集點促銷活動影響購買決策的關鍵因素。本研究採問卷調查，針對岡山區13-18歲的青少年，每次有新的集點促銷活動推出即會參與的國高中生為範疇。問卷共發放45份，回收42份，無效問卷為4份，有效問卷為38份，回收率達93.3%，有效問卷率達84.4%。研究結果顯示，探討心理層面、群體影響、個人特質對青少年購買決策關鍵因素中，以個人特質最具關鍵的影響構面，心理層面次之。其中前六大主要關鍵的評估準則為認知清澈度、贈品屬性、依賴互動、團體的吸引力、價值觀改變與主動建立關係。較不具關鍵影響的關鍵因素則為取悅他人與同儕壓力。

The purpose of research is to understand the effects on conformity for purchasing decision of bonus points promotion of teenagers through the use of Analytical Hierarch Process (AHP).It will also implement a literature review method and a compilation of expert opinion in outlining the key factors of above situation happened in 7-11 convenience stores. This use of an expert questionnaire method will be helpful to create an index that will ultimately be used with AHP to gauge the effectiveness of purchasing decision. A total of 45 questionnaires were sent to the students aged from 13 to 18 ,lived near Gang-shan District and have engaged in the bonus points promotion. A total of 42 were returned, with 38 valid ones, for a total of 93.3% return rate and 84.4% validity rate. The result of this research showed the most important key is the personal characteristics. Meanwhile, the prior consideration key factors is based on the psychological level. The main crucial five indexes are as follows: cognitive clarity, premium properties, dependent interaction, the attractiveness of the group, values change. The less critical indexes are to please others and peer pressure.