Ebook Central offers flexible perpetual purchasing models:
ProQuest Ebook Central offers flexible options in Demand Driven Acquistion (DDA) that can be combined with a subscription and perpetual access to build your online library.
Demand Driven Acquisition (DDA) is when the library creates a DDA profile or a set of criteria of books that they wish to make available to their patrons to access. The library will consult with ProQuest to determine a number of settings to create this DDA profile. Any books that fit the criteria of the DDA profile will be made available to their patrons via the patron platform, Ebook Central. In a DDA, the library is letting the patron drive purchasing and collection decisions but it also ensure that only books that are actively used are being purchased. At this point, the library has not purchased any of these books.
The patron can trigger for the library to make an automatic purchase of the book if they do any of the following:
Mediated Demand Driven Acquisition has an important element whereby instead of triggering an automatic purchase of the book should a patron attempt to download, copy or print the title, the book will appear as "Available on request". 
If a trigger is actioned, a pop up box will appear asking the patron to request the book from the library in LibCentral, under Patron Requests. The librarian must then decide whether they wish to approve or deny the request.
In LibCentral, under Patron Requests, the librarian can review the request that has been made by the patron. If the patron has filled in any details with their request, the librarian will be able to view it. The patron will need to provide their name email address as compulsory fields.
The librarian can choose how they wish to provide the book to the patron. The request details will also provide the access model options (NL, 1U, 3U or UA) available for purchasing as well as the price.
In this example, the book is only available in NL, 3U or 1U. The librarian can select the access model they wish and then click "Purchase eBook".
The librarian can also approve a request as a Short Term Loan (STL). If it's available, then the number of days and short term loan price will be available. To order a STL, the librarian must choose the STL, and then click "Approve STL" rather than "Purchase eBook".
The library can also choose to "Reject Request", which means the patron will not be able to access the book. In all situations, the patron will be sent an automated email letting them know whether their request has been approved or rejected.
Short Term Loans (STLs) is when the library rents the book for a set time from the publisher for a fee, rather than purchasing the book. Not all publishers offer STLs and the prices of STLs can vary between publishers. The STL prices, if available, are displayed in the Full Record of the title in LibCentral, alongside the Access Model and their prices as well.
There are a number of ways a library can incorporates STLs into their DDA. For more information, please contact us for a consultation to explore the best options for your library.
Access to Own (ATO) is a way to apply expenditure on access towards ownership. Instead of autopurchasing a whole book as part of your DDA, you can purchase it in sections, depending on the number of triggers. ATO can be run in parallel with short term loans (STLs). You decide which DDA titles are made available as ATO and which are STLs.
For a front list title, on the first trigger, you will purchase 55% of the book at the 1U list price. At the second trigger, you will purchase another 55%, at which the library will then own the book. Effectively, you will pay 110% of the 1U list price to use Access to Own. However, if users do not trigger the book a second time, then you will not ever pay the second 55%. This models caters to one off purchases and can be considered if the STL prices are too high.
For a back list title, there are 3 triggers at 35%, effectively paying 105% for the title.
There may be exceptions to this, for more information please contact ProQuest.
Evidence Based Acquisition (EBA) is a model that allows libraries to provide patrons with unlimited access to a publisher’s pool of content for a one-year period. At the end of the program after 12 months, librarians can choose which titles to purchase permanently for their collections based on usage, enabling more evidence-based purchases.
Librarians can choose an EBA program on Ebook Central with a variety of academic publishers. View the growing list of publishers page to know more about the list of participating publishers and request a demo.
EBA solution –benefits and values to customers
How it works:
As for the patron, it will be seamless access to the pool of content offered by the selected publishers.
Digital Course Reserve (DCR) titles are offered as digital textbooks and available to libraries using the Perpetual Access License (PAL) Model. Course Reserve titles are a cost-effective solution to provide students access to textbooks assigned by faculty for their courses.
Identifying Course Reserve Titles
Libraries can easily search and identify the DCR titles in the LibCentral acquisition catalog. On Advanced Search, the following options can be selected:
The search results will display the titles that are available for the Course Reserve model purchase and is labeled as Course Reserve. The Course Reserve icon is also displayed on the Full record page, the cart full order view, manage lists and mediated request form.
Maximum Concurrent Limit
Some of the Course Reserve titles have concurrent users limits. The number of the maximum concurrent access differs from publisher to publisher. An example: when the maximum concurrent users is indicated as 6 and if the library had already owned four 1-user copies and if the library decided to purchase additional copies they can purchase up to 2 additional 1-user copies, or upgrade one of their 1-user copies to 3-users. The maximum concurrent users limit is observed throughout the purchasing workflow and if it exceeds the limit, a notification or reminder will pop up to adjust the quantity to match the concurrent limit.
Hourly Loan option
Hourly loans are available for all owned titles including Non-Course Reserve titles. As for the Course Reserve titles, the maximum download period is 3 hours. The patron can select the option whether they want a 1, 2, or 3-hour loan when they download the book. As for the Non-course reserve titles, the hourly loan length is longer and patron can choose from 1 hour to 23 hours, when they download the title.
Hourly loans for Course Reserve titles is activated by default, no action needed in Libcentral. Libraries can choose to enable the hourly loan option for non-Course Reserve titles owned in 1-User or 3-User or Unlimited Access model at the Access Permissions settings in LibCentral, under the Owned tab. If the download option is deselected, then this will include the hourly loans. If the option to preserve reader access enabled, the same rule will be followed for the hourly loans.
For more information, please visit Digital Course Reserves on Ebook Central at ProQuest support center.