Hello Tim,
Read your last post. I am no longer really into the developer side of this unless I need it for a specific purpose.
However, in regards to PDF, I am simply busy all of the time. So I come across a lot of good articles about things but I don't have the time to sit at the site and read an entire article. So I can save a pdf file to read later in the evening when things slow down.
One site I visit a lot,
http://www.bizreport.com/ offers whitepapers usually in standard pdf format.
PDF files I'm guessing are a matter of personal opinion for many but for myself. I find them useful.
Just my thoughts,
Chris