The problem with PDFs
Jessica's statement of PDFs being a universal file format, regardless of operating system, is correct. However, the PDF format carries some major drawbacks for the user; primarily that it is a static, fixed display. Regardless of whether being displayed on a PC, MAC, Palm OS or Windows Mobile device, document structure does not change. In many cases, the print of the document is so small that in order for it to be readable, the user must zoom in. In many of those cases, the display must be zoomed in to the point where the entire page width will not fit on the screen of the monitor or handheld device, requiring the reader to scroll from left to right as well as up and down in order to read the document. Figure A below shows the main shortcoming of the PDF format.

FIGURE A


PDF files don't flow or paginate well. Roll over picture for a larger image.

As you can see in Figure B, the problem is even worse on a handheld; and this one has a 5-inch diagonal screen, it's much worse on smaller handhelds.

FIGURE B


PDF files are even worse on handheld devices. Roll over picture for a larger image.

And let me tell you, being forced to scroll left to right in order to read puts a very large damper on the satisfaction of reading a digital book. Perhaps this is the reason why digital books have not been as widely accepted as this reader would like them to be.

Other document readers will automatically reflow and paginate the document in order for the printing to be readable, yet still fit on the screen of the display device; not so with Acrobat or any other PDF reader I've used. If there is one that will do this, I'm simply not aware of it. But there's no denying that Adobe's Acrobat Reader is by far the most prevalent of all the PDF readers.

And, as Jessica stated, the cost of the full version of Adobe Acrobat, the version required for publishing your own documents, is not only expensive, for some people it seems downright exorbitant and unreasonable, as seems virtually all of Adobe's retail software. The full, Standard version of Adobe Acrobat 9 runs $300.00 from the Adobe store. Several other alternatives are capable not only of making a better ebook, but are much more cost efficient in the bargain.