OXFORD DICTIONARY.COM

This story has been widely reported. I've chosen two venues as the bases for this post:

"The head of Oxford University Press, Nigel Portwood, recently caused a stir by openly considering the possibility that the third edition of the Oxford English Dictionary might be published in electronic form only. What prompted those thoughts was the success of the online version of the O.E.D., as it is usually called, and the limited sales of the printed 20-volume edition."
(Source: http://www.nytimes.com/2010/09/01/opinion/01wed4.html?scp=1&sq=oxford%20print&st=cse)

We can intuit the reason without much effort, and a spokesperson for Oxford University Press confirmed that users prefer to look up words using its online product. Although I'm not a user of ebooks and remain a little skeptical about the notion that ebooks will eventually come to replace physical books altogether, I must admit that I haven't used a paper-based dictionary for English-language needs in quite a while. (Other languages are a different matter.) Read the story in more detail here.