Ok, here's a reason for you to switch

:
You're in your pajamas at 9pm and you just finished your last library book. You're not tired and want to continue reading something, but the library's closed & remember, you're in your pajamas!
If you had a Kindle, you could download a lot of samples of different books you've been curious about, without having to spend a single cent. All while sitting in your pajamas at 9pm.
Granted, the library is free; however, you have to consider the gas you use to drive there, the times the library is open for use, keeping track of due dates & possible late fees if you don't get the chance to finish a book in time, and the fact that you can't really go to the library in your pajamas.
Can you tell I'm a fan of sitting in my pajamas?
Most of the books I've purchased were books I would've purchased anyhow, but I had the chance to sample them first to be sure I would like them. Plus, I very rarely pay over $6 for a book, and it'll never fall apart on me with repeated readings, which is something I tend to do with certain books.
The dictionary has come in handy many times with just a couple clicks of the wheel, rather than having to grab a dictionary if I run into a word I'm not familiar with.
I can adjust the font size which has greatly reduced eye strain, allowing me to read longer than before. And now my bookcases can be freed up for other things---I don't know what yet, but I'm sure I'll think of something.