Acquisition Models

Libraries can acquire content in several different ways. Libraries can order titles one-by-one or as a collection. Collections may be organized by publication date, subject, vendor, or other structure. Some vendors let the library select a set number of titles to create their own collection.


Journals can be acquired by selecting and subscribing to individual titles or as part of a package. They can be subscribed to as an individual library, library system, or in consortia. Journal backfiles, permanent online archival access to past journal issues, are often purchased as a one-time expense.

Big Deals

A Big Deal is a large journal subscription package with all the included titles predetermined by the vendor. It is an alternative to purchasing journals on a title-by-title basis and can provide access to more content for less money than purchasing journals individually. Both individual libraries and library consortia enter into Big Deals. The individual cost-per-library is usually reduced when a group of libraries expresses interest. Whether Big Deals provide good value is a topic of debate and largely depends on the vendor’s terms and the institution’s values and needs. The value of Big Deal’s has been reassessed in recent years and academic libraries have explored walking away completely or breaking up their Big Deals.

Unsub is a commonly used tool for assessing the value of a Big Deal. It is important to make sure you understand its underlying assumptions by scanning the literature and speaking with other librarians. Price et al. (2021) has helpful advice on important factors to consider when using this tool.

Ebooks and Print Books

For the purposes of this section, books refers to both print books and ebooks. Specific formats will be referenced as appropriate.

Approval Plans

An is a collection of books that meet pre-specified criteria. The library gives the vendor guidelines such as desired subjects, price limits, and reading levels (e.g., undergraduate, professional). The vendor could be a publisher or a bookseller. The vendor notifies the library as books meeting those criteria become available. The vendor may send a title list that meets the library’s criteria or they may send the actual print book to the library. If a vendor automatically bills and sends print books this is referred to as a “Blanket Order.”

Firm Orders

A is when a library orders something as a one-time purchase. Usually this refers to purchasing individual books. The library and the vendor have not made any special arrangements about the order ahead of time. There are no obligations to reorder the content again in the future even when a new edition is published.

Standing Orders

Some titles release new editions, new volumes, or new books in a series, on a regular basis. A library may want to always purchase the newest edition or volume when it becomes available. Instead of placing a separate order each year the library can set up a standing order. A is an agreement to preorder each new edition or volume automatically. The vendor will simply send the newest edition or part to the library and charge the appropriate fee. A standing order can also refer to a journal subscription.

User-Driven Acquisitions (UDA)

User-Driven Acquisition (UDA) is an umbrella term to describe acquisition models that incorporate library patrons. There are multiple UDA models, but they are all similar in that patrons participate in the decision on what titles will be added to the collection.

Patron-Driven Acquisition (PDA)/Demand Driven Acquisition (DDA)

PDA and DDA are two names for the same program. In a PDA or DDA model, the library selects a set of titles to make available. The library loads information about those titles into their library catalog, discovery layer, or other ebook search tool. Patrons then discover and access the titles in the same way as they discover and access anything the library owns. If a title gets used enough times, it may trigger a usage fee for the library or an email to the selector for further review. With this model, the library only pays (or considers paying) for content that its patrons actually use. Be sure to check your contract to ensure the PDA/DDA vendor will allow you to stop the program at any time with no penalties.

Setup: Short Term Loans and Purchases

Many libraries choose to rent a title first and then purchase it upon subsequent uses. These ebook rentals are often referred to as Short Term Loans (STLs). For example, you could set up your PDA/DDA plan to do two STLs and then purchase the title outright on the third use. Or you could set up your plan to do one STL and buy on the second use. The price for an STL is usually a percentage of the total cost of that title and can vary widely by vendor. The cost may also change over time. Some PDA/DDA vendors may allow even further customization where factors like the price of the loan and the full price of the title can be considered. If that is the case, you could opt to purchase a title outright on the first use if it is over or under a certain amount. The amount you spend on STLs does not apply to purchase of the title. You will spend more than the full price of the book if the book ends up getting purchased. On the other hand, you can potentially save money if you have a lot of books that are only used one or two times and never trigger a full purchase.

The PDA/DDA vendor you are working with should be able to give you a list of the rates for different publishers. You may want to exclude certain publishers based on their rates. Some PDA/DDA vendors will also allow you to set a limit for STLs that will be the highest dollar amount and/or the highest percentage you are willing to pay. Each library makes its own decisions about how many STLs to allow before purchasing the title.

Setup: Profile

The setup process involves creating a profile that will determine which titles are made available to your patrons. This process is similar to developing an approval plan, and includes choosing factors such as subject area, publisher, and price. Depending on the vendor you work with, you can choose Library of Congress or National Library of Medicine call number ranges you would like to include. The vendor should also be able to give you a list of the publishers that are included and you can also choose to exclude publishers. For example, if you have access to a publisher’s content on another platform you will probably want to exclude them from the PDA/DDA plan so you don’t purchase content you already have. The PDA/DDA vendor may allow you to submit a list of ISBNs of books you already have so they can deduplicate against your existing holdings.

Assessment and Monitoring

It’s a good idea to monitor the plan, especially in the first several months. You will want to look at the titles in your profile to make sure they conform with the types of titles your library usually purchases. If you see a large number of titles that don’t fit your collection, work with your PDA/DDA vendor to have them removed.

You will also want to look at your expenditures to determine if you are using the right number of loans as a trigger to purchase. For instance, if you are seeing a lot of titles being purchased that are never used again, you could increase the STL trigger amount. Or you may see that you are spending more money than you would like on loans and want to purchase earlier. You will be able to change any of your settings and it may make sense to start off with conservative criteria and then make adjustments.

Access to Own (ATO)

Access to Own is the same as PDA/DDA except that the loans count towards the purchase of the title. Once the loans add up to at least 100% of the list price, the library will own the title. ATO loans are usually more expensive than STLs.

Evidence-Based Acquisitions (EBA)

In an EBA plan, the library works with a single publisher to get access to all or part of their title list for a certain amount of time, usually for a year. The library agrees to pay a certain amount of money up front to have unlimited access to the set of titles. They can then load the titles into their , , or search interface. At the end of the access period, they will be given usage reports to review. Titles can then be selected for outright purchase. The number of titles the library selects depends on the amount they paid up front and the cost of the desired titles. For example, if you pay $10,000 for your EBA plan you will be able to choose $10,000 worth of books to own perpetually. If you want to purchase more than that amount, your library will need to pay the difference.

Traditional Acquisitions vs. Inclusive Access

Traditionally, physical items (i.e., print books, print journals, DVDs, BluRay) are purchased for library collections so that one patron can borrow an item for a predetermined time period. Other patrons must wait for the item to be returned before it can be checked out to a second individual. Digital items are also shared among patrons, although how many users can view the item at a time depends on their license. Licenses for 1, 3, 5, or unlimited are the most common options offered by vendors.

With inclusive access, the library or institution purchases an individual copy for each person who will be using the material. Each patron gets their own copy of the content. Examples of inclusive access purchasing models are: using tuition or mandatory fees to cover the costs of those materials or setting aside a pool of money from the library budget to be used on an as-needed basis.

Streaming Media

Purchasing streaming media can be complex and depends on which platforms you have access to as well as your library’s ability to host content. It is common to see streaming media available to purchase as a with 1-, 3-, or 5-year licenses. Although these acquisitions function as a one-time firm order, the access licenses must be re-purchased after the term expires in order to continue access to the title. Streaming videos may also be purchased with perpetual access licenses, although typically these are sold as files that will need to be downloaded and hosted at your institution. For downloaded files, you will want to ask for a file that includes captions as well.

It is common for streaming media to move between platforms or not be available for libraries to purchase. In particular, titles that are exclusive to streaming platforms such as Hulu, Netflix, and Amazon Prime will often have no option for educational streaming rights.

To show films at a public event, you will need to obtain a license for Public Performance Rights (PPR). This may or may not be part of your license agreement and may cost extra. PPR is typically available for one-time showings but some vendors also offer perpetual PPR.

Agents & Acquisition Platforms

Agents are the companies that support libraries in finding and purchasing materials. Often agents act as third parties for procurement and payments – you submit your orders, invoices, and financial details to them and they pay the resource provider. Commonly used agents include GOBI (EBSCO), Rittenhouse, and Harrassowtiz.

Some agents have developed their own acquisition platforms. Acquisition platforms help libraries discover print books and ebooks to acquire (including the provision of approval plans and blanket orders), compare pricing between sources, and place orders. The pricing options available through these vary depending on the aggregator or publisher. They often include titles in disciplines beyond the health sciences although some specialize in health sciences topics (e.g., Matthews Book Company and Rittenhouse). In these tools, different permission levels can be set. For instance, some people may have permission to recommend titles but not place orders while others may be able to approve and submit orders.

In GOBI and OASIS, two well known acquisition platforms, libraries need to first set up or confirm licensing agreements with the publishers and vendors whose platforms they want to view. Both systems also have standard licensing agreements for many publishers and booksellers. Afterwards, specific titles can be searched through those tools to see which publishers and booksellers they’re able to purchase it from.

Select Vendors

This section briefly introduces some of the vendors that you may encounter as well as some of the bigger names in health sciences publishing. Libraries can order titles on an aggregator platform or directly from a publisher. The list is not exhaustive and is not an endorsement of any aggregator platform, publisher, vendor, or bookseller.


A vendor can aggregate, sell, and host titles from multiple publishers. For this type of vendor, content is aggregated in one interface, usually based on the type of content, although sometimes it can include a mix. For instance, they may offer one platform for ebooks from various publishers, another for streaming media, or the platform may include both.

Ordering through an aggregator can make it easier for library patrons to find, navigate, and use content from multiple publishers in a single interface. They may, however, include digital rights management (DRM) that can limit the number of pages a user can download or the ability to print, as well as have usage limitations or higher costs.

Aggregators have many benefits for institutions with limited staff time. One downside to aggregated databases with ebooks or multimedia is that the vendor/aggregator may add or remove titles at any time and with limited notice. You may receive an email from the vendor when titles are added or removed, but there may be limited or no options available to regain access to those titles.


EBSCO has ebook-only subscription packages that incorporate a variety of health sciences subjects. You can purchase firm order ebooks through them as well. The EBSCO platform is also an interface for subject databases like Cumulative Index of Nursing and Allied Health Literature (CINAHL), Health and Psychosocial Instruments (HaPI), and AgeLine.


ProQuest is a library aggregator that owns several other companies, such as the streaming media publisher Alexander Street Press which offers many health sciences titles and collections. They offer ebook subscription packages (e.g., Academic Complete) and the option to purchase individual ebook titles through firm orders. Their ebook hosting platform is called Ebook Central. The ProQuest platform is also an interface for subject-specific databases such as Dissertations & Theses.


Rittenhouse is an aggregator that specializes in health sciences print books and ebooks. As of Spring 2022, Rittenhouse ebooks are only sold with 1-user licenses, although multiple 1-user licenses may be purchased.

TDS Health

TDS (Teton Data Systems) Health is an aggregator that specializes in health sciences resources. They offer ebooks, reference tools, study aids, and test preparation tools. They use a subscription model for their ebooks, which are all part of the STAT!Ref Library. Subscription ebooks are selected on a title-by-title basis. As new editions of subscribed ebooks become available on the platform, the library’s access automatically updates.


A publisher is the company or person that prepares and publishes journals, books (print and electronic), media, cases, question banks, and other original content. Each publisher will have its own platform for hosting their content. Ordering titles directly from the publisher usually gives libraries the best pricing with the fewest limitations. It may be useful to be aware that the clinical side of the company will often have different reps from the other divisions. For example, you will likely have a different representative for ClinicalKey than ScienceDirect, even though they are both part of Elsevier.

Listed below are some of the largest publishers of health sciences content. You should, however, also consider purchasing from smaller or independent publishers in order to broaden the diversity of your collections contents, and to help prevent the monopolization of resources. Matthews Book Company and R2 Digital Library both list health sciences publishers that they work with on their websites, which include smaller publishers in addition to larger ones. Neither list is comprehensive but they serve as a good starting point for familiarizing yourself with what’s available.

It is worth noting that society publishers are increasingly having their back catalogs and frontlists bought and brokered through aggregators.


Elsevier publishes resources for the basic sciences and health professions. They have books, journals, multimedia, and procedure videos along with other educational resources. Other electronic resources that they sell include ClinicalKey, Embase, ScienceDirect, Scopus, and Mendeley.


McGraw-Hill’s flagship product is the Access-branded clinical specialty databases (e.g., AccessMedicine). The Access platforms include ebooks, study resources, multimedia, patient education handouts, and pharmacological information as well as other educational resources. They have an electronic library platform that offers a limited selection of individual firm order ebooks in the health disciplines. They also sell JAMAevidence, the First Aid series of ebooks, OMMBID, and USMLEasy.

Springer Nature

Springer Nature has DRM-free ebooks, journals, and databases. They sell frontlist ebook packages (i.e., ebooks for the upcoming year) and will also sell individual titles, as long as you meet a minimum purchase requirement. Their ebook library is called SpringerLink. Some of their other products include Springer Nature Experiments, SpringerMaterials, and SpringerProtocols.

Thieme (pronounced Tee-Mah)

Thieme publishes health sciences books, journals, cases, and interactive multimedia. They have a particularly strong emphasis on atlases. Their two main subscription products are the discipline-specific MedOne ebook and multimedia collections, and the Thieme Clinical Collection, which includes clinical titles for residents and practitioners.


Wiley sells journals, books, and various databases. Their subscription ebook packages are available via the Wiley Online Library platform, and libraries can also purchase individual titles. Wiley’s best known health sciences databases are The Cochrane Library and Essential Evidence Plus.

Wolters Kluwer (Ovid and Lippincott Williams & Wilkins)

Wolters Kluwer provides access to journals, books, multimedia, study resources, and other products. Wolters Kluwer is the parent company, Ovid is their online content provider/platform, and Lippincott Williams & Wilkins (LWW) is their publishing arm. They sell their own ebooks as well as ebooks by other publishers. They offer subscriptions to subject-specific Health Libraries as well as ebooks that can be purchased on a title-by-title basis. Other electronic resources that they sell include UpToDate, Lexicomp, FireCracker, and AudioDigest.

Online Courses for Professional Development

References and Further Reading

American Library Association. (n.d.). Glossary of technical services terms.

Blume, R. (2019). Balance in demand driven acquisitions: The importance of mindfulness and moderation when utilizing just in time collection development. Collection Management, 44(2-4), 105-116.

Falloon, K. A., & M. O’Reilly, F. (2020). Prioritizing accessibility in the E-resources procurement lifecycle: VPATs as a practical tool for E-resource acquisitions and remediation workflows at academic libraries. The Serials Librarian, 78(1-4), 130-140.

Gregory, V. (2019). Collection development and management for 21st century library collections: An introduction. American Library Association.

Chapter 5 covers acquisitions.

LaMagna, M., Swenson Danowitz, E., & Rodgers, A. (2020). “Competing ebook acquisition models: Which model best serves a community college library? Collection and Curation, 39(2), 33-40.

Price, J.S., Levine-Clark, M., & McDonald, J.D. (2021). Using the unbundling power of Unsub responsibly: Unveiling its assumptions and unpacking its defaults. In B. Bernhardt, L. Hinds, L. Meyer, & K. Strauch (Eds.), Charleston Conference proceedings 2020 (pp. 30-63). Against the Grain Media.

Vassar College Libraries. (2022, April 27). Approval plans. Collection development and management.

This webpage describes some of the strengths and weaknesses of approval plans.


Share This Book