Due in large part to the appearance since mid-2006 of increasingly affordable devices making use of e-Ink technology (a monochrome display supporting a high-resolution image despite low battery use, since the screen consumes power only during page refreshes, which in the case of ebooks generally represent page turns), the ebook has gone from a somewhat limited market into a real, although presently still niche, contender. Amazon sold 500,000 Kindles in 2008 ; Sony sold 300,000 of its Reader Digital Book model between October 2006 and October 2009. In September 2009, ebooks represented between 1% and 3% of the total US publishing market .
Following the JISC National eBooks Observatory Study  in the UK, one participant, David Nicolas, was quoted as stating that ebooks have 'reached the tipping point' . Keeping in mind Bohr's statement that, 'prediction is very difficult, especially about the future', it's nonetheless safe to say that publicity about these devices is currently at a high point. But for ebook readers, as Figure 1 shows, this is not their first time in the spotlight.
"A good book has no ending. ~R.D. Cumming"
This article marks the third time that Ariadne has discussed the subject of ebooks, namely "Ebooks in UK Libraries: Where are we now?"  and "e-Books for the Future: Here But Hiding?" . There is something very beguiling about the idea of a book that has 'the marvelous chameleon-like quality that it can very quickly be made to substitute for a different printed work by simply loading different content'  - a book that can play the role of a library.
As Striphas  points out, the concept of the electronic book, and the exploration of the interaction between the size of a container and the quantity of knowledge held, has an extraordinarily long history. He traces the idea back to the creation of miniature manuscript books, composed of 'tiny handwriting, or micrographia', in the late 15th century, which were functional objects and could be read by means of a magnifying glass.
Striphas notes the development of microphotography techniques in the 19th century. This was initially pioneered by John Benjamin Dancer, an optical instrument-maker who combined microscope and camera in order to create the earliest example of microphotography on record . Luther reports that 'the 21 May 1853 issue of Notes and Queries carried a letter from a Dublin scholar asking "May not photography be usefully applied to the making of catalogues of large libraries?' Microphotography led to the report in the British Photographic Journal of, 'A page of printing, from Quekett's "Treatise on the Microscope", reduced to such size that the whole of the volume of 560 pages could be contained in a space one inch long and half-an-inch broad ' .
By the end of the 19th century, Striphas reports, it became possible to speak of 'microphotographic books'. Robert Goldschmidt and Paul Otlet wrote about the livre microphotographique in 1907 ; by 1925, they described a print-on-demand library based on these technologies. Microform, and print-on-demand services, reached practical implementation in the 1920s-1930s , and was formally approved by the American Library Association in their Annual Meeting of 1936 . This trailed the first wartime use of microfilm by almost 60 years; microphotography of documents, in order to facilitate the use of pigeon post, first took place during the Franco-Prussian war of 1870-1871 – although it was first proposed many years earlier .
Microfilm libraries, both municipal and personal, are a common staple of science-fiction in the time of Heinlein and Asimov. In The Puppet Masters (1951), Heinlein describes a library in which books are selected via a catalogue and delivered via delivery tube to a study room in the form of bookspools. By the 1950s, Asimov  would write about reading-tapes and book-films. In the novellette Profession , he compares books, 'reading-tapes', and vocational education. Microform books were not commercialised outside the library environment, although it is evident from the text of patents such as 3280491, granted in 1966 to Jeshayahu Klein , that the potential for personal use had been recognised.
The use of micro-film, particularly in the instructional and educational field has become increasingly more adopted, the obvious advantages of such film as opposed to the larger forms needing no detailing. Currently used projectors [are] in the main too bulky to be readily portable [and] expensive to manufacture. Much useful information and instructive material is capable of being reproduced on micro-film. Such information [..] is reduced to an inexpensive minimum when reduced to micro-film. It is a primary object of my invention to provide a portable viewer for micro-film.
If adapted for current technologies, Klein's argument would not seem out of place today.
However, microfilm is hard to read, as evidenced by a 1976 letter from S. A. McCoy to a journal recommending a microfilm viewer, stating that 'this truly portable viewer has transformed working from films from a drudge into something approaching a pleasant experience' . McCoy adds that 'in case readers' natural cynicism has been engaged by the above, I have no connection with the firm who make it.' The ambition was there; the technology, it seems, was not.
Returning to Striphas' history, we find ourselves in the 1980s, with cable television companies trialling teletext services adapted for ebook reading – videotex. There were evident flaws; amongst them, expense, accessibility, and speed. Videotex was quickly abandoned in the USA. In France, Videotex caught on in the form of Télétel, but this was linked to a large investment from the French government. Equally, it was used mostly for interactive and - to some extent - reference services , but although it was viciously opposed by newspaper owners, it did not take a significant role as an electronic content delivery service, and so did not closely approach the role of the ebook.
By the late 1980s, the focus had moved to the personal computer, and remained there until it was rewarded by the 1998 release of the SoftBook, a device that had been in development since 1995 , and the 1999 release of the NuvoMedia Rocket ebook reader.
The SoftBook reader was about the size of a sheet of letter paper, weighed 1.3kg, had a 9.5 inch greyscale touchscreen. It cost $599.99 and contained a 33.6Kbps modem. Downloading new books was achieved by connecting the book to a telephone line, and was restricted to the US and Canada. The battery life was officially five hours, but reports suggest that the figure was closer to three or four. It contained 8MB of memory and made use of the same format as the NuvoMedia, a variant on HTML 4. If connected to the phone line overnight, it would download any periodical subscriptions for use the following day .
The NuvoMedia Rocket weighed 600g, had a 'postcard-size' monochrome LCD (Liquid Crystal Display) touchscreen and stylus, and claimed a battery life of 20 hours with the backlight on and 40 with it off. Users reported a more modest battery life in practice. It cost a more modest $199 for the basic model with 4MB of flash memory (16MB of flash for the Pro model at $269), but connectivity was limited to a serial port and cradle . Following a buyout of both companies by Gemstar, linking with Powells Books in the USA, and the subsequent publication of other ebook readers, Gemstar licensed the technology to Thomson, who subsequently manufactured versions of both the Rocket ebook and the SoftBook as the REB1100 and REB1200. Manufacturing was then taken up by Ebook Technologies.
In 2000, at the height of this hype, Stephen King released an ebook entitled Riding the Bullet. It was plagued with technical problems. A figure of 400,000 copies ordered in the first 24 hours was claimed , and servers quickly became overloaded. As the New York Times Magazine pointed out, 'The number of actual readers was another question because the encryption caused countless computers to crash'. . The Digital Rights Management (DRM) was subsequently defeated . It was the first of several ebook experiments for King, who later released part of a serialised novel, The Plant, in instalments – but stopped partway through, due to a drop in the number of paying subscribers. Most recently, King has been involved in marketing Amazon's next-generation Kindle ebook reader, for which he wrote the novella UR, available only for that platform.
Many ebook reader products have suffered from similar problems. It was anticipated by many commentators that two of them in particular, inadequate battery life and unsatisfactory screen readability, would be solved by a technology conceived at the MIT media lab and introduced in 1997. The first e-Ink reader, the Sony LIBRIé, was released in Japan in March 2004. In an interview in 2009, Russ Wilcox, joint founder of E Ink, described the launch as:
Critics loved the hardware, but there were only 1,000 books available, and that does not make a successful publishing market. And it turns out that e-books are a tough sell in Japan because there is a thriving used bookstore market.[...] At the same time, people were getting used to standing on trains and reading on their little cell-phone displays. 
The present resurgence in interest is fuelled by devices such as: the Sony Reader, launched – this time in the United States - in 2006; Amazon's original wireless Kindle, launched in 2007; the descendants of these devices, and the various other e-Ink devices currently on the market. The following part of this article discusses hardware, ebook device types, and other considerations such as cost and platform integration. In this article, a few general-purpose devices are also discussed – specifically, the iPod and Apple's new iPad. This is due to the fact that, in the US, the iPad's marketing places it within the range of devices used as an ebook reader. At the time of writing, Apple's iPad marketing in the UK does not yet mention this usage.
Since the vast majority of ebook readers presently on the market, other than general-purpose devices that contain ebook reading applications - iPhones, for example – depend on very similar e-Ink screens, the amount of variation in design is limited. Marshall , in describing a research prototype ebook reader called the Xlibris, explained its functionality in terms of a paper document metaphor.
In Marshall's words:
The device reproduces the physical experience of working with paper: readers can hold electronic documents on their laps, moving the e-reader as appropriate to avoid glare; they can mark on the electronic documents with a variety of pens and highlighters; and they can turn from one page to the next by thumbing on the device. In essence, Xlibris attempts to capture the materiality associated with reading physical documents.
Candidates for variation include screen size, weight and battery life. In general, the available screen sizes are between five and ten inches, with most common devices being based around six inches diagonally across from the bottom left to the top-right corner. The weight of ebook readers varies considerably. The same is true of battery life. The interaction between these characteristics is shown in the following table. Note that the impact of the bistable e-ink screen is very noticeable in terms of lengthened battery life when the display is continuously in use; the two devices containing colour screens, the iPod and iPad, have battery life based in hours rather than days when in use as reading devices. Steve Jobs of Apple is quoted in a recent interview  as stating that 'Ten hours is a long time, you're not going to read for 10 hours.' Frequent travellers with experience of economy-class long-haul flights – or students with experience of long days at university – may see it differently.
Other possible design choices include the following aspects:
Processor speed, which influences the speed of indexing, document access and rendering, is particularly relevant with regard to formats such as PDF that can prove relatively processor-intensive to display.
(Some screens offer eight shades of grey, whilst others offer 16). At present very few devices marketed specifically as ebook readers have colour screens, with the exception of the Apple iPad.
Operating system and opportunity for software installation and customisation are further aspects. Although the popular e-Ink screen has too low a refresh rate to use comfortably with responsive applications, not all devices marketed as ebook readers are dedicated solely to that purpose. Sony devices make use of a custom embedded operating system, whilst the iPad uses a similar operating system to the iPhone. It therefore benefits from the compatibility with Apple's App Store, while sharing the corresponding limitations of the operating system. The Barnes & Noble Nook makes use of the Android operating system, as a result of which it includes much wider format support than many other devices. Many other ebook readers make use of variants of Linux.
The amount of onboard memory influences the number of ebooks that can be stored. Expansion capability determines in particular the availability of a memory card slot such as a SDHC (Secure Digital High-Capacity) or Sony memory stick. This enables more books or other resources to be stored in the device than can be fitted into the device's onboard memory.
Audio capabilities may be added, such as onboard text-to-speech reading capabilities, or an MP3 player.
The most basic devices provide only a mechanism for moving forwards and backwards in the book, turning to an index, and selecting items. However, the ability to annotate as well as the ability to search for specific pieces of text is useful for many use cases. For this reason, some devices provide a physical keyboard, whilst devices with a touch-screen generally make use of an onscreen keyboard instead. This reduces the physical size of the device, since the off-screen real estate containing the keyboard is no longer required.
A few devices tie directly into distribution networks, such as the Amazon Kindle's link to Whispernet, enabling data to be downloaded live from most locations. The new Barnes & Noble ebook reader ties into Wi-Fi at bricks-and-mortar bookstores across the United States. Apple's iPad device is expected to make use of a service, imaginatively entitled iBooks, that will function in a similar manner to iTunes. This service has not been announced outside the United States. The iPad is not internationally marketed or intended as an ebook reader, but as a general-purpose media tablet. The 3G-enabled iPad model is therefore likely to provide 'Kindle-like' functionality in terms of quick access to eBooks. Most, however, depend on download via a PC and connection to the ebook reader via a USB connection.
Within these constraints, there is considerable scope for engineering, refinement, and variation.
|Device||Screen size (diag.)||Input||Connectivity||Grey-scale levels||Formats accepted||Memory||Text-to-speech||Built-in dict.||mp3|
|Apple iPad (note: Ebook store available only in US)||9.7 in.||Multitouch screen||Colour||Wifi, Bluetooth, 3G optional, Apple proprietary port||16GB, 32GB and 64GB model||?||Software available on App Store||Software available on App store.|
|IRex digital reader DR1000S||10.2 in.||Touch sensor input||USB||16||PDF, TXT, HTML, Mobipocket PRC, JPEG, PNG, GIF, TIFF and BMP. In future: DRM PDF/EPUB||1 GB Mini SD card slot||No||No||No|
|iRex iliad book edition||8.1 in.||Touch sensor input||USB||16||PDF , HTML TXT, JPG BMP, PNG PRC, mobipocket||128MB, expandable via USB, MMC, CF||No||yes||Yes – as user-created extension, mp3, ogg, flac, etc.|
|Amazon Kindle 2 International||6 in.||keyboard||Whisper-net mobile connection USB||16||† Kindle (AZW), TXT, unprotected MOBI, PRC||2 Gigs internal, no expansion slot||Yes||Yes||Audible , MP3|
|Kindle DX (available in US only)||9.7 in.||keyboard||Whisper-net mobile connection USB||16||† Kindle (AZW), PDF, TXT, unprotected MOBI, PRC||4 GB internal||Yes||Yes||Audible , MP3|
|B&N Nook||6 in.||Colour touchscreen||3G WiFi USB||16||Epub, ereader, PDF||2Gigs internal, microSD expansion||No||Yes||MP3|
|Cybook Opus||5 in||Touch-screen, accelerom-eter for auto-rotation of screen||USB||4||ePUB/PDF HTML, TXT, JPG, GIF, PNG, mobipocket via upgrade||1 GB internal and microSD||No||No||No|
|Sony PRS-300||5 in.||n/a||USB||8||LRF, PDF, TXT, RTF, ePub,JPG, GIF, PNG, BMP||512MB internal||No||No||No|
|Sony PRS-600||6 in||touchscreen||USB||8||LRF, PDF, TXT, RTF, ePub,JPG, GIF, PNG, BMP||512MB internal SDHC card Sony memory stick||No||Yes||MP3, AAC (non-DRM)|
|BeBook mini/ Hanlin V5||5 in.||n/a||USB (wifi projected to become available via extension card)||8||PDF, TXT, RTF, DOC, CHM, FB2, HTM,L, WOLF, DJVU, LIT, EPUB PPT, Mobipocket.||512MB internal, SDHC card expansion||Yes exper-imental||No||MP3|
|Cool-er ereader||6"||Resembles iPod style clickwheel||USB||8||PDF, EPUB, FB2, RTF, TXT, HTML, PRC, JPG||1GB storage SD card expansion||No||No||MP3|
|Apple iPad||9.6"||Touchscreen||Apple proprietary connecter, 3G (optional), Wifi||Colour||Various, including Apple-specific encryption/DRM on ePub format as standard||No expansion||?||?||Yes|
† Amazon provide a conversion service able to transform PDF, HTML, DOC, RTF, JPEG, GIF, PNG, BMP for use on the Kindle.
Note that SDHC cards are high-capacity secure digital cards, whilst SD cards are simply secure digital cards. SDHC cards are currently available up to 32GB (the limit of the specification), whilst the specification for SD cards limits their size to 4GB.
The base price for an ebook reader is, as of late 2009, around 180-220 GBP [*]. It is expected by some industry analysts to continue to fall in price over the course of 2010 and 2011 – Gartner's vice president predicts 2010 to be the year when e-book readers really become popular consumer electronic devices, culminating in e-reader 'mania' for the 2010 holiday season .
The Amazon Kindle is now available in an 'International' edition, as is the larger-format Kindle DX reader. They both offer wireless connectivity outside the United States, and can be used for immediate access and purchase of, mostly English-language, ebooks on the Amazon.com store.
A mess of ebook formats, lyrically referred to as 'The Tower of eBabel' , has grown up across the market, some driven by device vendors and hardware manufacturers, and some promoted by software vendors such as Adobe. The following table summarises several ebook formats.
|RTF (Rich Text Format)||.rtf||Microsoft||No||Widespread|
|HTML (Hypertext markup language)||.html||World wide web consortium||No||Widespread|
|PDF (Portable Document Format)||Adobe, released as ISO/IEC 32000-1:2008.||Yes, many standards. Adobe Digital Editions is commonly used.||Widespread support (with the exception of DRM)|
|eReader (Palm Media)||.pdb||Yes – encrypted with key||iPhone, PalmOS, Symbian, BlackBerry, Windows Mobile Pocket PC/Smartphone, desktop Windows, and Macintosh|
|Mobipocket, precursor to the ePub format.||.prc, .mobi||Open Ebook – International Digital Publishing Forum||Yes|
|ePub||.epub||OEBPS  - International Digital Publishing Forum||Yes|
|Broadband ebooks||.lrf, .lrx||Sony proprietary||Yes||Sony devices, and desktop Windows, Linux and MacOS via Calibre|
|Kindle||.azw||Amazon proprietary (similar but not compatible with mobipocket)||Yes||Kindle|
As the market continues to take shape, there are moves towards standardisation. Barnes & Noble are currently launching the Nook ebook reader, and announced in October 2009 that the device will support ePub. Sony moved away from its proprietary .LRF (BroadBand eBook, or BbeB) file format towards the ePub format. As such, some describe ePub as the MP3 of the ebook world. Like the MP3 format, the ePub format is well supported with reader software on many other platforms, including desktop operating systems, iPhone/iPod Touch, Android, Maemo and Windows Mobile. It is claimed that the Stanza reader alone has one million users. An exception is the Amazon Kindle, which does not natively support ePub, requiring a conversion tool to be used.
At the time of writing, book retailers in the UK offered ebooks in the following formats:
|Retailer||Supported formats||Ebooks available (as of Autumn 09)|
|WH Smith||Epub, Mobipocket, Adobe PDF, Microsoft||50,000|
|Borders||Epub and/or PDF depending on title||50,000|
|Amazon US||Kindle/Amazon proprietary format, available in the UK since 19 October 2009 (see notes). Certain other formats usable via conversion offered by Amazon at $US 0.99 /1Mb||Over 360,000 in the USA|
Ebooks might be expected to be less expensive than their dead-tree cousins. After all, no wood pulp is involved in their construction, storage requirements are very small and even shipping and handling becomes a relatively minor consideration. However, the prices are scarcely attractive – Kindle International users pay around $US12 for a recent Amazon ebook (~8GBP) , although some e-books will be cheaper. Although this is expensive by comparison to most mass-market paperbacks, it is significantly cheaper than the cost of ebooks from most other US ebook retailers – Barnes & Noble are up to 50% more expensive  - and reflects the fact that Amazon treat their ebooks as loss-leaders put in place in order to render the Kindle more attractive and increase market share. Amazon is said to lose $US2 for each ebook sold , and $US4 for each bestseller .
Amazon CEO Jeff Bezos is quoted  as saying that 'E-books should be cheaper than physical books. Readers are going to demand that, and they are right because there are so many supply chain efficiencies relative to printing a paper book.' Publishers, however, disagree.
In a recent spat with Macmillan, who asked Amazon to allow them to set prices higher than $US9.99, arguing that the rate 'was too low and putting pricing pressure on their physical books' , Amazon temporarily removed the ability to directly buy Macmillan books, physical or electronic, from Amazon. Macmillan, however, prevailed; their preferred pricing model, known as the 'agency model', stipulates that books will initially be offered from $12.99 to $14.99 when initially released, with prices changing over time.
Some commentators see interviews such as this recent discussion between Apple's Steve Jobs and Mossberg  as a demonstration that Jobs and Bezos are simply on opposite sides of the battlefield. Bezos described his vision of Amazon as 'the world's most consumer-centric company'; recent quotes from Jobs, on the other hand, suggest that the publisher is king. As might be expected, it's all rather more complicated   for further discussion about the issue. A particularly readable description of an author's perspective may be obtained from John Scalzi .
In UK-based stores, prices appear almost identical to their dead-tree counterparts. This can be seen in the following graph, which was generated by comparing the cost in each store of ten randomly selected books in physical and ebook formats (carried out in November 2009). Note that the Amazon US values are somewhat misleading, in that certain of the books selected were on sale only within the United States. As can be seen, the UK-based booksellers surveyed here charge somewhat more for ebooks than for paper books. Note also that Borders UK went into administration in November 2009 and closed its doors in mid-December 2009, so these numbers are included here for interest only.
A final word regarding the cost of ebooks. As it stands today, paper books are alone in being exempt from VAT (Value Added Tax which equates roughly to US sales tax) . Within the European Union, audiobooks and ebooks are considered taxable . In the UK, full VAT rates are charged on ebooks and 0% VAT on paper books, whilst in Holland, 19% tax is charged on ebooks, against a 0% rate on paper books (in France and Germany, paper books are taxed at 5.5% and 7% respectively). Similarly, downloads of journal articles from the British Library also attract full UK VAT rates.
In February 2009, the EU voted to permit member states to reduce VAT to its minimum value on certain items, including audiobooks and ebooks . Whether individual governments elect to do so is another question entirely, but the option to do so now lies in the hands of EU national governments.
Barnes & Noble in the USA state that 'eBooks follow the normal tax rules of all downloadable products.' 
DRM, or digital rights management, is generally applied to the majority of commercially published files, whether released in ePub, PDF, Amazon's own Kindle format, or other formats. The limitations imposed by DRM vary; usually the user is permitted to make use of books on a number of registered devices; this precludes the lending of books to others in most cases. This sort of difficulty was highlighted by Richard Stallman, in his 1997 article, The Right To Read . A further problem with DRM, particularly in a commercial context, is the close link to a specific distribution network, meaning that different types of device may not be eligible for registration – bought works cannot usually be transformed between formats or applied to different types of devices, except when explicitly supported by the distribution organisation.
A second approach to distribution limitation is offered by the sort of device lockdown applied by Apple – that is, a newly bought iPod Touch or iPhone cannot run arbitrary code, but only code distributed by Apple. This formally discourages pirating, but also limits customisation and hobbyist software development. In response to this, large communities have grown up around the concept of jailbreaking Apple devices – getting a level of control over the device that enables individuals to instal software without having to go via Apple's official distribution network. This was originally intended to enable individuals to use custom ringtones and wallpapers . Jailbreaking is now popular enough that a company offering applications for jailbroken devices estimates that 10% of iPhone and iPod touch users have jailbroken their devices .
As with many means of digital rights management, most popular DRM mechanisms have been broken, including MobiPocket and, hence, at least one of the DRM approaches used for the Kindle , and Adobe's ADEPT DRM, as is commonly applied to ePub and PDFs . The Topaz format also used on the Kindle – a PDF-like format that allows more complex display – has also been reported to have been broken . This leaves most ebook platforms in much the same place as the erstwhile iTunes DRM; since a workaround is widely available and technically uncomplicated, many individuals are able to use it where it fits their needs.
One common argument against DRM is that those who will suffer most are not those who profit from the unauthorised redistribution of content – but the less technically inclined end-users who want to use their content in a manner not specifically permitted by the distributor, such as reading an ebook on a platform not covered by the distribution scheme. For many owners of ebook readers and general-purpose mobile devices, DRM – like the choice to jailbreak their iPod, and similar closed distribution channels in general - is more of an inconvenience than a showstopper. But underneath that level of consumer confidence in grey or aftermarket solutions, there are sinister undercurrents. If DRM mechanisms are tied to a central service, and that service goes away for whatever reason, what happens to readers who have not taken the extraordinary measure of stripping DRM from their content? For example, with the demise of Borders, what has happened to those who bought ebooks from that source?
In mid-2009, Amazon provided a graphical demonstration; a third-party publisher submitted a number of ebooks for sale. Amazon initially accepted them, but later removed the ebooks from sale following notification by the rights-holder. They then removed copies of the unauthorised publication from their books and their customers' devices, notifying customers via an emailed refund statement. In short, customers who had bought in good faith copies of Orwell's 1984 and Animal Farm found that the books had simply disappeared from their Kindle devices. The media attention following this literally Orwellian episode led Amazon to state that should the situation recur, they would not remove books from customers' devices . The occurrence has nonetheless caused many to ask: should customers be reassured that the policy of Amazon is now that it will not unilaterally delete books purchased in good faith, or should the consumer remain concerned about the fact that, demonstrably, Amazon – and presumably other retailers with similar distribution models – could once again resort to 'after-sales deletion'?
A previous sticking point in the adoption of ebook reader platforms again arose from its interaction with the traditional publishing world. The Kindle, like several other platforms, contains a text-to-speech mechanism. In the case of the Kindle, it is known as Read-to-me, and an example of its use is currently available . It does not appear capable of fully supporting accessibility for the visually impaired, in that the Kindle cannot read out the contents of the menu system, but only the book itself . In fact, this limitation has prompted legal action relating to the decision by several universities to take part in a pilot programme testing the device, and Amazon has signalled its intention to remedy this limitation .
In the meantime, publishers reacted strongly to the appearance of a text-to-speech function. Paul Aiken, executive director of the Authors Guild, is quoted as saying, 'They don't have the right to read a book out loud. That's an audio right, which is derivative under copyright law.'  As a result, Amazon has now provided publishers with the right to switch this function on or off on a per-book basis.
Overall, these devices fit into three broad categories; general-purpose devices that can be used as ebook readers, as well as other uses, and specialised devices that attempt to emulate the experience of reading a book – which themselves fit into two broad categories, depending on whether they are designed as part of a specified ebook distribution network or not.
For example, the Sony Cybook and Cool-er devices are not specialised; although Sony owns its own ebook store, it is equally possible to make use of other stores selling ebooks in compatible formats, such as Baen Free Library  and Books On Board . As Books On Board explains , it is possible to upload non-DRM-bearing book titles to the Kindle, but 'premium' (DRM-bearing) titles cannot be used on the device. Certain devices are not simply a piece of hardware, but a multi-platform distribution and reader system. By comparison, the Sony reader devices, along with certain others in a similar category, are not limited to a single 'premium-content' distribution system, but are relatively open and agnostic of distribution system – with the exception of a preference for certain formats, such as PDF and ePub over Mobipocket. A single device is not usually able to support more than a subset of formats, primarily for licensing reasons; Mobipocket reputedly disallows Mobipocket DRM and Adobe DRM from co-existing in the same device .
Buying into certain ebook platforms is a user experience similar to that of buying a mobile phone, in that some hardware platforms are designed and sold under the assumption of significant ongoing vendor tie-in; it is important to find a distribution network, a library, that coincides with one's requirements. An ebook reader without a commercial distribution network is primarily a gateway into the classics, open content and user-generated content, whilst an ebook reader with a single distribution network is a gateway into one vendor's world. Clifford Lynch wrote in 2001 that ebook readers raise questions about 'the future character and operation of personal digital libraries, and their relationship to commercial and non-commercial digital libraries and digital bookstores', and about 'how these entities will be distributed across a mix of portable appliances, personal computers, personal storage on network servers, and institutionally or commercially controlled storage and services on the network.' 
From the users' perspective, it seems unlikely that the sort of manoeuvrings involved in the present situation will benefit them; content is encumbered, prices are negotiated in a manner that is both unclear and involving significant grandstanding, and as the recent collapse of Borders UK has shown, buying into anything other than an open platform with open content requires a very sincere and complete risk assessment. The collapse of previous ebook infrastructure has demonstrated that devices may last longer than the supply network. This is mitigated by devices that make use of cross-vendor standards; those with unsupported proprietary devices will have to hope that a community is able to find a solution to their difficulties.
It is to be hoped that over time, the situation regarding digital rights management will be resolved. In the case of music sales, it is now commonplace to buy music in the form of unencrypted MP3 content that can be played back on any platform. Indeed, given the difficulties of retaining a large collection of files even without the additional challenge of artificially limited playback, it is to be hoped that the user be given a great deal of support. At the price of current commercial ebook content – and given that there is generally no mechanism provided for resale of licences, and thus no mechanism to transfer the ebook to another reader - an ebook collection is a very significant investment. In the meantime, it is perhaps inevitable that many ebook owners will take advantage of the existence of solutions to remove access control on their files.
If universities are to become involved in this type of infrastructure, it would seem strongly recommended to limit exposure to the use of these devices to read compatible, open content; for this purpose, there exists a number of very appropriate devices on the market today. Students can recoup a great deal of the original cost of their coursebooks on the resale market. The same is not true of electronic books. Accessibility remains an issue across the board, and therefore it is suggested that any adoption of electronic book readers be accompanied by an appropriate strategy to ensure that these concerns and needs are met.
As an owner of an e Ink device, I am optimistic about the future of these devices – especially when twinned with content stores such as the Baen Free Library. Moreover, I regularly meet people who express a very evident delight in the idea of a book that can contain all of their favourite reads. I am less optimistic about the idea of buying into a specific distribution network; far better, one might argue, to seek distributor-agnostic solutions – perhaps even to make use of the buying power of universities as a group, rather than to limit oneself to the constraints of any single solution.