There is a great interview in Library Journal (from February 11, 2014 authored by Ian Chant) featuring Ashley Eklof , who is the librarian in charge of the BiblioTech which the first all-digital library in the United States. See http://lj.libraryjournal.com/2014/02/technology/who-needs-books-a-qa-with-the-bookless-library-head-librarian/ for details. BiblioTech is located in Bexar County near San Antonio, Texas.
A couple of points are worth noting here:
1) Although this is an all-digital library the library still needs human librarians to provide customer service and technical support to patrons. In other words there is still a need to have a human presence within the library as technology alone is not able to provide patrons with all the services they are looking for. In reading through the interview it is clear that the major obstacle in using the digital services is getting started with using the technology and patrons prefer to seek out human assistance to learn how to use the technology. As technology constantly innovates and evolves the learning experience will most likely not diminish in complexity. Eklof indicates in the interview that her staffs are keeping busy meeting the demand.
2) There is patron demand out there for this type of all-digital library, as Eklof notes that 300 people a day visit the library.
3) The digital library in fact does allow for a reduction of traditional library work in terms of eliminating the need to physically monitor the collection by continuously weeding or checking the ILS (integrated library system) for physical materials that are missing from the collection. As Eklof states digital library materials are either checked in or checked out, they are never lost or missing. Another advantage here is the fact that items are automatically returned on time so there are no late fees. The advantage of this is that the librarians can spend their energy/time to assist patrons and to create/market programming. No longer do they have to spend a lot of time doing collection oriented work. A possible disadvantage is that librarians may not become as familiar with the interests of their patrons by the sheer fact that they cannot physically see the actual print books that are going out or coming in. Another possible disadvantage is that there would have to be a new approach to marketing the library collection. No longer would a nice display of actual print books or physical items be possible.
4) The creation of a digital library has allowed there to be other digital library services made available to the public. Consider the kiosk that BiblioTech opened at the Bexar County courthouse. The 500 people entering the courthouse each day for jury related duties can have access to digital library services. This is a rather ingenious idea in that it allows for a broad collection of library materials/services to be made available to a large patron constituency without taking up the large space to house a traditional print collection.
My own thoughts are that this model of library service may very well be replicated nationwide. However, I would imagine that this type of library would be a specialized type of library (similar to library services established solely for incarcerated or homebound patrons) within the traditional public library branch structure. In other words each public library system would have one or two library branches created entirely for digital only services while the rest of the library branches would remain concentrated on the current blend of traditional as well electronic library services.