PDF is a versatile document format that is supported by many different programs and devices. So why not convert your documents or even ebooks into this versatile format.
Software for Windows and Mac OS X computers as well as apps for different smartphones can open PDF files. Even most web browsers such as Chrome and Firefox can display a PDF. The same goes for most ebook readers. If you can't find the correct ebook format for your reader or are sick of converting back and forth, converting to PDF is a safe bet.