Optimize PDF Files for Search Engine

Portable Document Format (PDF) is the file format for presenting device-independent documents on and off the Web. PDFs are an efficient way to accurately describe simple to intricate documents for screen or print output. A PDF document is a collection of objects with structural information in a self-contained series of bytes. PDF is a page description language, like PostScript but simplified with restricted functionality (no programming like PostScript) to be more lightweight.
There are some PDF optimization Tips:
Creating Small PDFs
Avoid Refried Graphics
Use Vector Graphics
Minimize Fonts
Make sure your PDFs are text based.
Build links into PDFs
Pay attention to the version
Optimize the file size for search
Pay attention to placement
Specify the reading order
Tag your PDFs