圖書館在兼顧豐富館藏量與滿足使用者需求之經費緊縮困境下，通常會以加入相關電子書聯盟方式，藉由其聯合採購增加購買力，降低採購電子書相關成本，提供讀者電子書服務，並同時建立館際間的聯合電子館藏，以達到資源共享之目的。經由聯盟所採購之電子書館藏，因其資源共享政策，提供給圖書館讀者所能使用之圖書數量，都大於圖書館所購買者。就單位成本可使用之圖書數量，似乎顯示電子書成本低之優勢。但在「每本書均有其讀者」與「每位讀者均有其書」之定律下，電子書館藏不能僅就其購置單價論定其成效，而應從讀者實際之電子書使用成本效益與滿意度，評估其對圖書館之效益。因此本研究首先提出以圖書被使用之單位時間成本為探討圖書使用成本效益之基礎，藉由某國立大學圖書館紙本圖書與電子書之實際使用數據及花費成本，個案說明分析比較紙本圖書與電子書之使用效益。接著利用LibQUAL+(上标 TM)量表與網站使用性評估準則，以問卷方式瞭解使用者對個案圖書館所提供電子書服務之滿意度與使用性。在同時考量讀者於電子書使用成本效益與服務滿意之電子書對圖書館效益，提出大學圖書館經營現有電子書館藏之建議以供參考。

With growing user demands and tightening budgets, many university libraries are opting to join consortia to purchase and share electronic books. Through cooperative acquisitions, libraries may reduce the cost of electronic books and at the same time provide users with access to wider resources. Bearing in mind the perspectives of "every book its reader" and "every reader his book," however, decisions on whether to acquire electronic books should not be based on cost only. Use of electronic books and cost effectiveness for libraries should be taken into consideration. This study first compared the cost effectiveness of paper and electronic book usages in a university library. It then used the LibQUAL+(superscript TM) measures and web usability criteria to evaluate user satisfaction and usefulness of that library's electronicbook services. Findings of this study may offer useful insights for managing electronic-book services in university libraries.