I've heard family and friends say that they'd be willing to pay a little more for DVDs and Blu Rays if it meant skipping ads and things like that. This is a little like that. A new Kindle is coming May 3 that costs $25 less, but the price is sitting through some "well-placed ads." But Kindle/Amazon isn't using the term "ads." They're calling it a "Kindle with special offers."
One difference I've heard with these ads is the ability to vote on the types of ads through their web site and the AdMash Kindle app.
I think I'll stick with my iPad e-reader.