No argument from me.  I just said image for lack of a better term.  However, copying text from a pdf is very much a hit or miss event.  It depends up on the viewer you are using to read them.  They all seem to handle copying to the clip board differently.  I have used some viewers that would not copy at all.  It also depends up the "locks" that were placed on the pdf when it was created.  You can get into a lot of factors here.