Out of curiosity, how many readers are switching mostly to Kindle books? I myself find myself doing this. Not for any ideological or conscious reason. Rather, cost and portability are both major upsides of the Kindle. I also find that “impulse buys” are easier for me on the Kindle (purchased The Great Sea and Civilization: The West and the Rest, the latter mostly to see if Panjak Mishra actually did read the book). The Kindle has been around for a few years, but it looks like web traffic related to it is still increasing radically. I compare it o the iPad below.
Update: OK, never mind about the comparison. I suspect that the bounce for “Kindle” is due to Kindle Fire.