When posting a PDF file you must also assume
that your audience does not have the software to view your file. You can post
a link to a site where they can obtain the necessary software. This example
uses Adobe Systems. A file can only be converted to pdf fomat using specific
software such as Adobe Acrobat 3. There are two drawbacks to this method of
displaying text: 1. It uses alot of memory especially if there are a lot of
illustrations involved. 2. When displaying a copy of your published paper you
may be violating copywrite laws.
To illustrate this effect I have
included a link to ASU's Department of Molecular and Cellular Biology
Frontiers in Biotechnology link: pdf