I strongly think a kindle is not something a kid would warm up to. As a kid (3-9), I really loved books with illustrations a lot more than text heavy books. I think a kindle will not be as interesting as a graphic book at that age. But, for someone who is 14 and above a Kindle would be a good addition.
Also, the only book I have bought in one month of owning a kindle is "The Girl Who Kicked The Hornests Nest". I dont think books are the attraction for me with the kindle - it is the ability to read long-form articles on the web that I find hard to read on my laptop or desktop. There is, of course, the added advantage of ePub books from, ahem, trusted sources, working remarkably well on the Kindle. I bought a kindle last-minute for a trip to Australia, and it has served me very well there (mainly as my sole means of checking email and twitter). Those who have the propensity to buy books (as opposed to borrowing from library) would be the people for whom a Kindle would be of greatest benefit as a book reader. I am glad I have an awesome library nearby so I do not have to do this, so Kindle has become the device I use to "read with focus". - divya
