Use Mobipocket software to convert PDFs to that format so you can read them on Kindle.
Ebook readers have extremely high contrast/readability and are extremely energy-efficient, being able to display several thousand pages of material without needing to recharge. eBooks are a narrow product, but they have their own ways in which PMPs cannot compete.
DRM is not to prevent other files from being readable on the Kindle.
Think about waiting somewhere in the middle of the day, or perhaps in an airport while you're traveling, and having immediate access to 100,000 books and hundreds of newspapers and periodicals from this pad in your hand.
A revolutionary portable reader that wirelessly downloads books, newspapers, magazines and blogs to a crisp, high-resolution electronic paper display that looks and reads like real paper, even in bright sunlight.