Actually making such versions freely available seems to be good
business for some. See:
I suspect that attaching a CDR to each book, with the full
contents, would not harm sales. In fact, it might enhance them for
such people as peetah. People who want paper will still want
paper, and may even be encouraged to get it by reading from a pdf
or ps or html version. The html version would be preferred, since
it is easily searched with text utilities, and is most adaptive to
screen and paper sizes. The minor disadvantage (not present with a
CDR version) is that pictures and diagrams have to be separate
files. See how baen does it.
Also, Plauger and Brodie's "Standard C A Reference Manual" was not
only supplied with a copy on floppy, but explicit permission was
granted to make it accessible on networks, including the web.