Because I have a whole bunch of technical documents that I’d like to be able to carry around and read on a device that is not my laptop.

(And yes, I could have ordered a cheap touch-screen laptop, but I’d also like to be able to order and download books from Amazon as well as O’Reilly (who makes their books available as PDFs at a discount) as well as papers from ACM. The ePaper screen also makes the thing highly readable outside.)