When cutting and pasting from a PDF, I always seem to have to put a little work into re-formatting, fixing characters like apostrophes that don't come across right, etc. Not a big deal, but that's why a RTF file would be nice (you could include it in the same .zip file) - or at least much appreciated by .01% of your audience!
For this reason, one of the things that's been on my to-do list is making the original .rtf files for our books available as a download for registered owners, to make it easier for players to create campaign folders, for publishers to re-use our OGC, etc.