Demand-Driven Acquisitions: Do Library Patrons Get What They Need?

In the years and decades leading up to the digital revolution, academic librarians often questioned how much of the content they acquired in print really got used. Did the books they purchased in advance via approval plans and other methods get used enough to justify the cost of the library’s largely speculative buying? Were those books they bought really what library patrons needed in the first place? Then the universe of content exploded online and overnight, it seemed, an ocean of digital books became available—some for purchase, some via subscriptions, some free (e.g., Project Gutenberg). New ways of building library collections content emerged—ways that would allow librarians to gain valuable insight into patron activities and answer the decades-old question at the heart of collection development: Are libraries acquiring what patrons need?

The last few years have seen a steady proliferation of business models used for selling and acquiring ebooks by libraries, each with a unique set of benefits and challenges, but no other model has held as much promise to give patrons what they needed—at the moment they needed it—as Demand-Driven Acquisitions (DDA), also known as Patron-Driven Acquisitions (PDA). This is because at its core, DDA places the user (the patron), not the librarian or the publisher, in the driver seat. For the first time in the history of institutional book buying, patrons decide, for a portion of titles, what the library collects, leaving publishers and vendors without the predictability they enjoyed for many decades before ebooks came around.

Why were so many libraries and vendors happy to give up control at first? Hasn’t the industry invested the past two decades in the argument that quality will always trump quantity in research and that content filtered by professionals—not random users, even if they were savvy researchers—is far superior to what is freely available online? And haven’t we also argued that information literacy—the ability to find and evaluate information at hand—in and of itself needs to be taught and learned? The simple, and somewhat paradoxical, answer is: by giving up control all sides would eventually benefit. For libraries, it meant that a larger pool of titles would be immediately available for discovery—the titles they would never buy outright—and this in turn meant that the library would be able to support their patrons’ research at the point of need. For publishers, it meant incremental revenue and more revenue from the backlist that libraries either overlook or never have any intention of buying through other means. And for patrons, the ultimate beneficiaries, it meant that they would have immediate access to what they needed when they needed it, while remaining blissfully unaware that their actions were driving the buying.

The only way to know for sure that the DDA model made sense for everyone in the chain of creating, distributing, and using ebooks was to try it. And try we have. For the better part of the last decade, libraries around the world have been experimenting with DDA, while publishers and aggregators, in cooperation with libraries, came up with various versions of DDA that would give libraries as much flexibility as possible. Indeed, the promise of the DDA model was that by giving up control and predictable outcomes and allowing users to lead the way would reward everyone in the long run. Countless case studies and several revisions of the model later, the industry stands at a crossroads. Has DDA fulfilled its promise? Has it proven that the ultimate indicator of value is the patron’s interaction with a title? Is DDA sustainable long term for all? Who decides?

Many DDA pilots conducted in various library settings (small and large) showed early on that the model provided substantial financial savings for libraries (e.g., Grand Valley State University Libraries, MI, ConnectNY, The Pennsylvania Academic Library Consortium, Inc., Auckland University of Technology, New Zealand, University of Huddersfield, UK), but as the model evolved, the experimenting on both library and publisher side has led to some unexpected outcomes. The letting go and letting users point the way, which many welcomed in the beginning, has also led to the lack of predictability, which neither side is comfortable with. In fact, it could be argued that the very lack of control embraced early on has resulted in both sides asserting more control than they do with other models (e.g., approval plans, subscription packages). This was evident in the frequent changing of DDA rules by librarians to adjust what was being purchased and when, and the subsequent increases of ebook prices and Short-Term Loans (STL) by publishers to adjust what was gained from the little revenue they were getting from mere sampling (vs. actual full title purchasing). Although no definitive conclusions can be drawn yet about where to go from here, it is clear that the DDA model has shown both libraries and publishers it is time for some introspection.

* * *

DDA has been described in myriad ways—philosophically and practically—in countless magazine and journal articles published in the past few years. There has also been no shortage of opinions on DDA in professional blog posts, webinars, and panel discussions. We’ve heard DDA described as a radical shift in the process from a librarian’s ‘just in case’ to a patron’s ‘just in time’ decision; a shift from speculative buying to evidence-based buying; a shift from focusing on the future need (as with approval plans) to focusing on the present need; and a shift from pre-selected to user-selected acquisition. Some warned the industry early on that DDA might lead libraries in the direction of spending large sums of money only to develop skewed collections of little general interest, while others sought to prove that user-selected books ended up getting more usage down the line than those acquired by librarians, thus helping to create practical collections in line with current scholarly pursuits. All of this raises questions about the purpose of a scholarly collection, of a librarian, and of the role of the academic library itself.

As disruptive as these descriptions sound, the story of DDA in libraries has for the most part been evolutionary rather than revolutionary. The model has undergone several incarnations since its inception, owing to both libraries’ and vendors’ continuous adjustments of ‘DDA rules’ to protect bottom lines and eliminate as much unpredictability from the equation as possible. What started out as a use-driven model designed to automatically trigger purchases based on how much a patron interacts with an ebook (in terms of, for example, pages used, printed, or downloaded) evolved into a complex model based on a predetermined set of rules that libraries could change frequently and that more and more incorporated the STL option into DDA, which especially made sense if libraries were less interested in ownership and more interested in providing immediate access.

In a relatively short time, DDA went from a rather straight-forward model with simple parameters that usually included the so-called 10-10-1-1 paradigm (automatic purchase triggered after ten minutes of continued usage, ten unique page views, or after any printing, copying, and downloading activity) to a model that could be molded ad nauseam to fit each library’s unique needs. And these needs often included the STL option, which quickly presented itself as a faster and cheaper replacement for ILL (Interlibrary Loan). The goal of STLs was to stretch the library’s budget by forestalling payment as much as possible because when STL is an integral part of DDA, an automatic trigger will only take place if a certain number of STL transactions occur. In other words, patrons are able to ‘sample’ more content than ever, and libraries will pay little for it before committing to a purchase.

Indeed, the perceived advantages of the DDA model for libraries were many from the start, including, among others: the immediate availability of a large number of titles that could never be purchased in advance; decrease in cost-per-use over time; flexibility to change the DDA rules as the library saw fit; more discoverable backlist that the library would not consider purchasing; substantial evidence that library money is always spent on actual reading; alignment of library collections with current user requirements; immediate availability of time-sensitive materials; proof that titles purchased represented titles that were used at least once if not more; and the ability to defer payment by relying on STLs to delay purchasing, especially of expensive titles beyond the scope of approval plans.

* * *

Although a number of publishers and vendors agreed to participate in DDA pilots with libraries, they slowly learned that what made sense to libraries did not make as much sense to them. At first, it appeared that they, too, would benefit from exposing more titles for discovery but, in reality, very few of those titles available via DDA were resulting in actual purchases at list price, which led to considerable revenue losses across the spectrum. According to data analyzed by GOBI Library Solutions (formerly YBP), just three percent of DDA records usually result in a purchase. A much larger number generate one or more STLs. On average, 70 percent of all transactions are STLs.

The predictability and consistency of other models (such as, for example, approval plans and subscription packages), which guaranteed at least some return on investment for publishers and aggregators, was no longer there with DDA. This made it challenging to guide future decisions and predict how long it would take publishers to recoup the costs of publishing. As Oxford University Press’ Rebecca Seger and Lenny Allen noted in Against the Grain (“STL: A Publisher’s Perspective”) publishers and aggregators did not expect the loss of revenue to be the main outcome of the DDA experiment. Seger and Allen also point to some misconceptions about the upfront cost of producing a scholarly monograph (which for OUP averages $10,000 for a 336-page title) and its subsequent sales (which average between 350 and 700 copies), so “receiving 10 percent of the cost of a book when it is used [and without it being purchased], and then having to share that 10 percent with both the aggregator and the author, simply cannot make financial sense to anyone.”

In Academic E-Books: Publishers, Librarians, and Users, a collection of essays by Purdue University Press exploring the challenges of ebook buying in academic libraries from a variety of positions, a number of contributors echoed the voices of concerned publishers, from Tony Sanfilippo’s (Ohio Univ. Press) “one thing is immediately clear: this model is guaranteed to delay the majority of a title’s revenue until one year after publication” to Rhonda Herman’s (McFarland) “revenue has fallen too quickly so inaction is simply not an option.” Upon seeing the detrimental effects of DDA on their livelihood, many publishers reacted in a way that was to be expected: they began raising the cost of one-day and seven-day STLs (in some cases by 100 and 200 percent), withdrawing frontlist titles from the DDA pool, or withdrawing from the STL model entirely. Needless to add, many other publishers that never warmed up to patron-driven purchasing and never took part to begin with (and this is not a short list) were now even more reluctant to join after seeing the struggles of their colleagues. Roughly 350 publishers have participated to some degree in DDA out of the more than 1400 on GOBI Library Solutions’ Approval Publisher list. The number dwindles swiftly once we remove the small publishers and those that allow less than 50 percent of their list in the model.

This turn of events has left librarians to question the long-term effects of the DDA model on library collections, which now stand to look radically different without a large number of publishers participating and/or a substantial number of key titles no longer available for discovery owing to embargoes and withdrawals. Then there is the question of keeping up with the rising prices of STLs, which, if publishers are to justify participating in DDA moving forward, are not likely to go away. Many have, in fact, already dropped out of STL completely. Now that the model has had time to grow, and both libraries and publishers are able to look back and compare notes, it’s becoming evident that publishers and vendors aren’t the only ones bringing attention to the hard-to-ignore shortfalls of the DDA model. Libraries that have participated in large and successful DDA pilots have reported challenges beyond those that have to do with disappearing content and price increases.

* * *

Even some early adopters and long-time fans of STL-based DDA are adjusting their perspectives. Doug Way, who, during his time as Head of Collections at Grand Valley State University Libraries established what was at that time one of the largest DDA programs at any library (and for which he offered insight in “Financial Implications of Demand-Driven Acquisitions: A Case Study of the Value of Short-Term Loans”), still sees benefits of the STL-based DDA for certain institutions, but not for all. “One of the challenges we’re faced with in libraries today is this one-size-fits-all mentality; this thinking that what works in a community college works great in an ARL,” he says. Now Associate University Librarian for Collections and Research Services at University of Wisconsin, Madison, Way has recognized the limitations of the DDA model in a top-tier public research university which is big in size (43,000 students and 5000 faculty) as well as big on usage of library resources.

According to Way, the library dropped its STL-based DDA program due to four challenges. The first was scale. The program had a $100,000 annual budget, but because of high level of use, the library was only able to make 23,000 titles available in the candidate pool. “We wanted to make more ebooks available, as we were seeing increasing demand. This would have required a significant increase in funds, which were not available,” explains Way. The second challenge had to do with workflows and policies. While it has been argued that DDA would free librarians to assist in research because less time would be spent on buying and maintenance, integration of DDA with existing workflows has shown to be a time-consuming endeavor, with libraries often experiencing technical and implementation difficulties, which has added complexity to the workflow. The third challenge, as expected, was the significant increase in the price of ebooks and STLs. “Price increases meant that many of our top-used publishers had priced themselves out of our candidate pool,” adds Way. The last challenge had to do with title availability and the developing trend where more and more high-demand content was being pulled from DDA pools by publishers.

“Our ebook strategy today can be seen as a layered approach,” says Way. “We view something like a subscription-based package as a base layer providing access to a lot of content across disciplines at a relatively low cost. For stability, we purchase high-use titles to ensure they are there into the future. On top of that layer we purchase a number of publisher-direct packages, especially from the larger STEM publishers. There is an additional layer of data-driven acquisitions—both DDA (non-STL) and Evidence-Based Acquisitions (EBA) models are being experimented with—and then we top things off with firm orders, which make a small percentage of our ebook acquisitions.”

EBA, which could be perceived as a cousin of DDA or a modification of DDA to make it more sustainable for publishers, gives libraries access to a set of titles for a pre-agreed amount. At the end of the agreed period, the library purchases the most used titles up to that amount. The downside for libraries, of course, is that there is no way of knowing that there will be a sufficient number of used titles to justify upfront spending. “When I was at smaller institutions, I didn’t like EBA programs because our use wasn’t high enough to justify the cost. At UW, that’s not the case,” explains Way. EBA makes sense, from a publisher perspective, on their own platform (e.g., Cambridge University Press, Elsevier), because they earn 100 percent of the revenue. But it is probably not sustainable as an aggregator model, because each publisher stands to earn much less in the process, and in the meantime, will earn less from other sales as the library is likely to turn off other purchase options.

The question inevitably arises: do data-driven acquisitions (whether DDA or EBA) ever make sense in small research libraries with low usage? Although Way saw benefits of STL-based DDA when he implemented it at Grand Valley State, librarians like Matthew Sheehy of Brandeis University, an institute with a strong undergraduate arts program and less than 6000 students, point to the model’s pitfalls even in small research settings. Sheehy says Brandeis eliminated STLs in some of its DDA programs as the percentage of the full cost rose to 30 percent or more, but goes further: “While it has been shown that DDA books get used more, at what expense to future scholarship?” he asks, adding. “These programs do not allow for a focused research collection that anticipates the future need. And they leave gaps in collective collecting. One DDA advantage is that a savvy faculty member (or student) could shape our collection, but one real disadvantage is that a bias can be introduced without us knowing, and to counter that bias we may need to spend on content we may not use.”

STL has also created problems at Brandeis when someone annotates a book, and the library does not end up purchasing it through DDA because it never hit the trigger. “Now we have an unhappy patron and while we have been able to successfully resolve these occurrences, it is a lot of staff time and a hit to our reputation,” explains Sheehy. Another concern has been the instability of consortia DDA programs like the Boston Library Consortium, which Brandeis has taken part in. “When partners pull out, mostly because of the success (demand = expense) of the program, we are left with lower discounts and higher costs, or we choose to withdraw as well.”

CTW Consortium (Connecticut College, Trinity College and Wesleyan University) Librarian for Collaborative Projects, Lorraine Huddy, echoes the sentiments of Way and Sheehy, believing in the basic philosophy behind DDA and its promise to balance library wants with research needs in light of budget cuts, however, she, too, points to it falling short in the long term and becoming increasingly unsustainable. Ebook prices and the cost of STLs will continue to go up, content choices will continue to shrink, and access issues will ensue, she says.

CTW has done DDA both ways—with and without STLs—but Huddy notes the preference is probably without STLs since students and faculty may browse many books before finding the information they’re looking for. “When they find what they need, indicated by downloads/printing/copy-pasting, we’re willing to buy the book. A five-minute browse is not necessarily long enough to find what you’re looking for in an ebook, especially when the platform is new to the user.” Huddy elaborated on her early DDA experience in “Striving for Insights and Contending with Limitations: The Assessment of a Collaborative eBook Project,” ultimately concluding that the transition to ebooks is still underway and that the user experience will play a significant role in how the future of library collections is shaped.

* * *

Examples such as University of Wisconsin, Brandeis, and the CTW Consortium point to librarians in dissimilar research settings coming to similar conclusions: Although showing evidence that patrons often choose relevant content and that libraries save significantly when only purchasing titles that show heavy use, DDA cannot be considered a core method of purchasing but instead a supplemental one—ideal for enhancing, rather than replacing, traditional methods such as approval plans, title-by-title ordering, or subscription packages. Regardless of the library size, it seems, DDA purchasing leaves visible gaps in the process, as publishers and aggregators struggle to meet libraries half way and as libraries struggle to meet user expectations.

The theory of the DDA has been that by giving up control, all in the ecosystem would reap the benefits. The practice has shown that benefits are there for some and never materialize for others. And those benefits are proving to be short-lived not only for libraries but, more importantly, for patrons, who will soon get less and less exposure to the titles they really need, and this will have effects not only on their overall experience but on the future of library collections. Unavailability of titles may lead patrons in the direction of less desirable titles which they will settle on, resulting in the ‘automatic’ creation of inferior library collections, or patrons will look elsewhere (beyond the library), resulting in an undesirable perception of the institution.

Perhaps the ultimate lesson of the DDA experiment has been that libraries and publishers have more in common than they may realize: both rely on predictability to drive spending and purchasing; both must control fixed budgets that require, at least to some extent, fixed returns on investments; both will adjust the rules to protect their bottom lines as often as needed; both want to invest in products and services to sustain their livelihoods; and, most important, both are on a mission to support scholarship in a way that leads to robust, multi-faceted, usable, accessible, and sustainable collections. Which brings us back to the decades-old question at the heart of collection development: Are libraries acquiring what patrons need?



Garskof, Jeremy & others. “Towards the Collective Collection: Lessons Learned from PALCI’s DDA Pilot Projects and Next Steps.” Collaborative Librarianship: Vol. 8, Iss. 2, 2016.

Harloe, Bart & others. “What’s the Use of Use?: Return on Investment Strategies for Consortial DDA Programs.” Journal of Library Administration: Vol. 55, Iss. 3, 2015.

Huddy, Lorraine. “Striving for Insights and Contending with Limitations: The Assessment of a Collaborative eBook Project. Against the Grain: Vol. 24, Iss. 4, 2012.

Rowsell, Glenda & Gillian Barthorpe. “Developing Collection Development Practices: Demand Driven Acquisitions — the AUT Experience.” LIANZA Conference 2014, 12-15 October, Auckland New Zealand: Pou Whakairo: Connect and Thrive.

Seger, Rebecca & Lenny Allen. “STL: A Publisher’s Perspective.” Against the Grain, November, 2015.

Stone, Graham & Briony Heyhoe-Pullar. “The Customer Is Always Right? Assessing the Value of Patron-Driven Acquisition at the University of Huddersfield.” Insights: Vol. 28, Iss. 1, 2015.

Ward, Susan M. & others, eds. Academic E-Books: Publishers, Librarians, and Users. Purdue Univ. Press, 2016.

Way, Doug & Garrison, Julie A., “Financial Implications of Demand-Driven Acquisitions: A Case Study of the Value of Short Term Loans.” Books and Contributions to Books: Vol. 1, 2011.

Zeoli, Michael. “Academic E-Books: Publishers, Librarians, and Users.” Against the Grain, November, 2015.

Zhang, Yin & others. “Notes on Operations: A Scenario Analysis of Demand-Driven Acquisition (DDA) of E-Books in Libraries.” Library Resources & Technical Services: Vol. 59, No. 2, 2015.

2 thoughts on “Demand-Driven Acquisitions: Do Library Patrons Get What They Need?”

Comments are closed.