Depending on the app that created such PDF and the settings/fonts used, you may end up with a pdf that is a bunch of font character bitmaps in sequence or blocked with no underlining text information. Most adobe applications will enbed textual versions in the PDF so the text selection tool can be used to grab plain text from segments in the pdf. I think the point is unles you can be certian how the pdf is generated and you are comfortable with them -- parsing data from them is going to be a large pain in the butt.

-Waswas