搜尋引擎特有的「關鍵字廣告」，其濫觴與主導平台Google有著「不為惡」的信條，標榜平台的中立特性，也倚賴著大眾對於平台所設計機制的信任與隱私的保護。然而平台在機制的設計中，使否存在破壞競爭、中立性以獲取利潤的空間？本文以Varian (2007, 2009)的模型為基礎，討論當廣告商使用關鍵字廣告獲取點擊數時，廠商的最適決策、與廠商間的交互關係，並考慮了平台自身、平台與廣告商之間，可能產生的限制競爭狀況。文章中驗證了(1)廣告商多個關鍵字的兩種目標函數極大化，並討論(2)廠商間在極大化目標函數下的競租行為：「濫用關鍵字」；之後討論(3)平台操弄關鍵字廣告機制，增加自身不當獲利的可能，最後(4)討論廣告商勾結平台，勾結雙方皆不當得利，卻損害其他參與者的狀況。

As a special part of search engine, the first and dominate platform of keyword advertisement, Google, has the brief of “Don’t Be Evil”. Platform depends on the trust of mechanism-designing and privacy-protecting, and also emphasizes the neutrality of itself. Does it has chance that platform with unjust enrichment sabotages competition and neutrality via the mechanism? The paper is based on the model of Varian (2007, 2009). We shows the optimal strategy and interaction of advertisers who acquire the clicks by keyword advertisement. Meanwhile, we take competing-restriction into consideration between platform and advertisers There is some features in detail, such as (1) maximizing the two kinds objective functions with multiple keywords in advertisers. (2) the rent-seeking behavior of advertisers under the maximizing. And the situation of (3) platform with unjust enrichment manipulates the mechanism of keyword advertisement. At last, we discuss (4) the collusion of platform and advertiser. It leads the collusion profit and damaging the other participants.

目　錄
論文審定書　i
誌　謝　ii
摘　要　iii
圖　次　vi
表　次　vi
第一章 緒論　1
　　第一節　研究背景　1
　　第二節　研究目的　2
　　第三節　研究架構　3
第二章 網路廣告現況與發展　5
　　第一節　近年網路廣告的規模與特性　5
　　第二節　網路廣告平台爭議近況　12
　　第三節　關鍵字廣告糾紛案例　16
第三章 文獻探討　20
　　第一節　關鍵字廣告的價格決定機制　20
　　第二節　關鍵字廣告市場之參與者行為　22
　　第三節　關鍵字廣告平台之議題與規範　25
第四章 模型與分析　28
　　第一節　基礎模型　28
　　第二節　廣告商之廠商行為　32
　　第三節　關鍵字平台之廠商行為　37
第五章 結論與政策建議　44
參考文獻　46
附錄　50
　　附錄一　Google AdWord廣告品質說明文件　50
　　附錄二　點擊數最大化過程　52

中文部分
　柴志斌譯，Ken Auletta 著，Google大未來，206-206，新北市，八旗文化(2011)。
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