Thanks to Jan in Wisconsin for sending me an interesting article on search engines and PDFs. A few years ago most search engines did not track PDF documents. Most of them are smarter now. It’s still not the best way to go but there are plenty of times where PDF makes sense and I thought I’d share a few ways to help PDF rank higher:
Write the document as you would a web page for ranking purposes. Use lots of good keyword terms – especially near the top of the document.
Be sure to add a title and meta tags – you can do this in the document properties. Titles are always important – meta tags are less important but still valuable.
Build links into the PDF document. This is good for the PDF and the pages to which it links.
Pay attention to version and size. Search engines don’t like large files – so try to optimize PDF for size. And saving for Acrobat 7 will ensure that more search engines can read it. (Acrobat 8 is out there but still pretty new.)
Don’t bury the document. As with all web documents you don’t want to store it away in numerous folders – leading to very deep links. It’s harder for the search engines to track those pages.
You can read the original article here http://searchengineland.com/070912-095906.php
Byte of the Week 
Using these basic guidelines for PDF SEO will ensure your pdf does well in Search Engines. I do want to reiterate one point that the PDF should still appear in your website and not be hanging. Hanging in the sense it does not have text links to it and from it. Make sure it fits into the overall structure of your site. I have found that in order for it to rank well it must use the meta tags available in the properties of the document.
Nice post. Not many people talk about SEO for pdf documents.
Thanks for the informative article. I’ve noticed that Google often ranks PDF’s quite higly in search results (usually when there aren’t many other results, especially local).
For this reason, I’ve started adding a few well optimized PDFs to some of my sites to see if they draw any traffic. Will keep you posted!