Several have commented on my post from this morning on Paula Fredriksen's PDFs. As predicted, when I got to class today, almost everyone had struggled with reading the article I had set (and in case you are thinking, "Excuses, excuses", that is not normal for Duke students, at least not in my limited experience so far).
But to comment on the post's comments, Eric Rowe notes that there are plenty of programmes available for converting originals to PDFs, and for free too. I use these myself, but I suppose that what holds others back are (1) the desire to have the document exactly as it appeared in print, with page numbers et al, rather than in the flawed original from their own PC; (2) the fact that research assistants and support staff are often those who prepare materials for scholars' homepages, and they work with what they are given, in this case printed originals. Some (not all) scholars who have homepages do not look carefully at the content on the page.
Crystal asks about why people use PDFs at all. I think the answer there is sheer convenience -- instant results. I know that that is why I've used them in the past, and with some regret because it takes away one of the glories of publishing on the web, which is hypertext. I know that in theory you can add hyperlinks (and so on) to your PDF, but in practice few do. One of the things I particularly dislike about PDFs of articles is the reading of footnotes and endnotes. The web offers the potential of a new way of reading academic papers, with nice, hyperlinked notes, but how often do we have that pleasure now that so many just upload a PDF?
A further relevant point: one of the advantages of the PDF adapted from the scholar's own e-original is that it can still be searchable, whereas the photo-scans of printed versions are usually not.
John Lyons asks about how publishers regard the uploading of scholars' work to the web. My own experience would be to suggest that they remain wary about the wholesale uploading of book manuscripts to the web, but appreciate that the reproduction of journal and FS articles can increase a scholar's profile and so increase book sales. But that's just my own perspective, and it may be inaccurate.