E‐books are available to academic libraries through a wide variety of acquisition models. The University of California, Merced (UC Merced) Library has used demand‐driven acquisitions (DDA) as its principal model for providing access to e‐books from its founding in 2005 to the present. This paper will discuss the influence of the situation at UC Merced on the implementation of DDA plans for e‐books and the results of the most recent five years of operations of these plans. E‐Books at UC Merced The University of California, Merced (UC Merced), the tenth campus in the University of California system and the first new American research university in the 21st century, welcomed its first class in 2005. The initial class comprised 875 students, mostly undergraduates. In fall 2015, UC Merced had 6,700 students including almost 400 graduate students. There is a proposal currently under review to construct sufficient academic buildings and student housing to allow the campus to grow to 10,000 students including 1,000 graduate students by 2020. From the beginning, e‐books have been a very important component of collection development at UC Merced. At the present time the library has approximately 1.2 million e‐books available and a print collection of approximately 125,000 volumes. Of the 1.2 million available e‐books, 800,000 volumes are available through University of California system‐wide package licenses with publishers such as Springer, Wiley, and Elsevier. In a majority of cases negotiations for system‐wide e‐book packages are linked to negotiations for journal packages from the same publishers. This trend has accelerated during the past five years. The remaining 400,000 e‐books are available through a variety of locally licensed models: 128,000 through an ebrary Academic Complete subscription; 216,000 through an EBL demand‐ driven acquisitions (DDA) plan with purchase on the fourth use after three short‐term loans (STLs); and 55,000 through a DDA plan with MyiLibrary with purchase on the second use without STLs. The Academic Complete subscription provides access to a wide variety of academic titles with unlimited simultaneous users for a very low per title cost. A potential disadvantage is that if the subscription were to be allowed to lapse, all access would be lost. Since UC Merced anticipates being able to maintain the subscription for the foreseeable future, this is not an issue. One of the main reasons for choosing EBL as the library’s principal e‐book aggregator, was EBL’s use of “non‐linear lending.” This model is not quite unlimited simultaneous users, but it’s close. The model allows a specified number of accesses during a calendar year, usually 300 or 325, before an additional copy needs to be purchased to maintain access to that title. The number of accesses resets each calendar year. This model is extremely useful when faculty assign e‐books for class reading. If these books were available with 1‐ user or even 3‐user licenses, the number of turnaways and the resulting frustration could be significant. At UC Merced only one title available under “non‐linear lending” has exceeded the number of allowed uses over ten years. The MyiLibrary DDA plan was originally implemented to provide access to titles not available from EBL. It was also an experiment with a different DDA model that didn’t involve the use of STLs. Since the fall of 2014 the MyiLibrary plan has also been used to provide access to titles that Copyright of this contribution remains in the name of the author(s). http://dx.doi.org/10.5703/1288284316306 Patron‐Driven Acquisitions and Interlibrary Loan 488 certain publishers were no longer making available through DDA plans with STLs. Content from publishers that no longer support DDA plans of any type is no longer available at UC Merced except for a small number of titles individually purchased. According to ProQuest the EBL and ebrary catalogues should be combined by the end of 2015. The EBL catalogue has already been deduped against ebrary Academic Complete at UC Merced. The library is currently in the process of examining the new publishers currently with ebrary that will be available when the two catalogues are merged. At this point a number of non‐academic publishers have been excluded from the plan. Other publishers may be excluded in the future based on willingness to support short‐term loans, the cost of STLs, and the availability of titles under non‐linear lending licenses. Now that ProQuest has also acquired MyiLibrary, the expectation is that there will be one unified catalogue of all ProQuest e‐books in the not too distant future. Having almost 275,000 e‐books available through DDA is contrary to the collection development practices of most research libraries that carefully circumscribe the size of their DDA pools by subject, publisher, publication year, etc. in order to guard against possible runaway costs. Other than blocking most titles in Library of Congress class R (medicine, nursing, dentistry, etc.), removing certain non‐academic publishers and having a $300 per title price limit, there have been no other substantial restrictions on the size of the DDA pool at UC Merced. There is specifically no limit by publication year. The library chose to take this approach primarily due to the rapid, uncoordinated increase in faculty hiring and in the establishment of new programs resulting from the university being in a start‐up mode for the first decade of its existence. Both the administration and faculty have tried to expand academic offerings as quickly as possible. Often this has resulted in hiring an individual faculty member in a field that is completely new at UC Merced. In many cases the library did not know that the faculty member had been hired until he or she appeared at the library to request book purchases and journal subscriptions. Since many new faculty, particularly in the humanities, have research agendas that are not shared by other UC Merced faculty, they often request information resources that are not useful to other faculty or programs. These conditions made it practically impossible to manage the DDA plans in the traditional manner. Another reason for taking this approach is that the library did not have and still does not have a sufficient number of librarians to have assigned subject selectors. There simply aren’t enough people to do title‐by‐title selection either for print or electronic monographs. Because of the emphasis on interdisciplinary work, UC Merced does not have traditional academic departments. Faculty have self‐ organized into various groups based on disciplinary or cross‐disciplinary working relationships. These organizational factors have also made it difficult for the library to initiate and maintain discussions with faculty regarding collection development. Under these circumstances, the best way to support teaching and research has been to cast a wide net with the DDA plans. As academic hiring becomes more stable, it is anticipated that the DDA pool will become more focused. The experience of UC Merced with the EBL DDA plan for the five‐year period from July 1, 2010 through June 30, 2015 is shown in the following statistics: Total spend: $337, 785