隨著數位經濟的迅速發展，訂閱制逐漸成為各大外送、購物和影音服務等平台的重要營運模式。本研究旨在探討在一個獨佔市場中，僅有高價和低價兩家廠商時，消費者訂閱行為對平台利潤的影響。
考慮消費者將運費及產品費用視為同一心理帳戶，並將其區分為經濟人（理性消費者）和自然人（非理性消費者），根據第三需求理論和沉默成本，分析訂閱前後的購買行為變化。我們認為訂閱前，多數使用者會認為運費較高傾向選擇高價產品，但使用者通常會購買運費較低的低價產品。訂閱後，自然人的消費頻率增加，特別是在無低消門檻的情況下，更傾向選擇低價產品，相反，在有低消門檻的情況下，會傾向選擇過低消門檻的高價產品，因此平台總利潤得以提高。
為了驗證我們的猜想，實際對10位訂閱者進行訪談，並建立數學模型。研究結果顯示，訂閱制能夠有效提高平台的利潤，為平台業者制定策略提供參考。

With the rapid development of the digital economy, subscription models have increasingly become a crucial business strategy for major platforms, including delivery, shopping, and streaming services. This study aims to analyze how consumer subscription behavior affects platform profits in a monopolistic market with only two vendors: a high-priced vendor and a low-priced vendor.
Based on the third laws of demand, considered consumers' perception of shipping fees and product costs within the same mental account. We categorize consumers into rational and irrational types. According to the third demand theory, irrational consumers alter their purchasing decisions. Analyzing changes in purchasing behavior before and after subscription, we hypothesize that before subscribing, most users tend to opt for higher-priced products due to the perceived higher shipping costs, while they typically purchase lower-priced products with lower shipping fees. After subscribing, the sunk cost of the membership fee will increase purchase frequency but lead consumers to choose lower-priced products. Without a minimum spending threshold, consumers will select very low-priced products. In contrast, with a minimum threshold, consumers will pick higher-priced products that meet the threshold, resulting in higher platform profits.
To validate our hypothesis, we conducted interviews with 10 subscribers and established a mathematical model. The research findings indicate that subscription models can effectively enhance platform profitability, providing valuable insights for platform operators in formulating strategies.

論文審定書 ……………………………………………………………… i
致謝 ……………………………………………………………………… ii
中文摘要 …………………………………………………………………iii
英文摘要 …………………………………………………………………iv
目錄 ……………………………………………………………………… v
圖目錄 .…………………………………………………………………. vii
表目錄 …………………………………………………………………. viii
第壹章 緒論 ………………………………………………… 1
第一節 研究背景 ………………………………………………… 1
第二節 研究動機 ………………………………………………… 2
第一節 研究目的 ………………………………………………… 2
第四節 研究設計與流程 ………………………………………… 3
第貳章 文獻回顧 ……………………………………………… 5
第一節 第三需求理論 …………………………………………… 5
第二節 沉默成本 ………………………………………………… 6
第三節 心理帳戶 ………………………………………………… 7
第四節 賽局理論 ………………………………………………… 9
第五節 理性vs.不理性的消費者 ………………………………. 10
第六節 外送平台 ……………………………………………….. 12
第七節 訂閱制 ………………………………………………….. 13
第參章 研究方法 ……………………………………………… 15
第一節 訪談大綱 ………………………………………….…… 15
第二節 賽局模型 ………………………………………….…… 16
第三節 賽局設定 ………………………………………….…… 17
第肆章 研究結果 ………………………………………………. 21
第一節 訪談分析 ………………………………………….…… 21
第二節 訪談結果 ………………………………………………. 22
第三節 模型討論 ………………………………………………. 23
第四節 策略討論 ………………………………………………. 32
第伍章 討論與建議 …………………………………………… 33
第一節 研究結論 ………………………………………………. 33
第二節 研究限制與未來建議 …………………………………. 34
參考文獻………………………………………………………… 36
附錄……………………………………………………………… 41

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二、網路資源
1. MIC資策會產業情報研究所(2024).【外送大調查】外送市場邁向M型化71%網友使用、訂閱成長5% 兩大龍頭差距擴大16% 市場經營策略出現定位區隔
2. MIC資策會產業情報研究所(2022).【外送大調查】72%消費者使用過外送服務 18~35歲最愛用31%已訂閱 50%會員平均每次消費300元以上
3. MIC資策會產業情報研究所(2020). 11%臺灣網友疫情期間首度使用美食外送服務